You arrive standing on the dock. Go forward, up the steps to your left, then left along the walkway, then right up the steps to path of wooden planks. On the ground nearby you'll find an interesting letter. Read it. Explore the island.
Years ago, Atrus father, Gehn, took him to D'ni and instructed him in the Art of Writing. Through time, Atrus realized his father—who believed himself a god—was insane. Atrus fled, but was caught and imprisoned in their island mansion. There, he discovered the Riven book. On Riven, he met an intruiging young woman—Catherine. Catherine introduced Atrus to a simple, beautiful Age called Myst. Atrus and Catherine joined to trap Gehn on Riven, then began a new life on Myst.
For the complete story, read Myst: The Book of Atrus.
Atrus letter speaks of a message in the forechamber by the dock. Go back to the dock and you'll find where you linked in, embedded in the earth is a metal panel. Inside, you'll find Atrus' dimensional imager.
Going down the steps, the panel is just to your right at the bottom. Click the small button to open it and and enter the number of marker switches on the island (08).
Click the button on the front of the dimensional imager to see Atrus' message to his wife, Catherine.
The marker switches are located at the... dock, gears, planetarium, spaceship, pillar walkway, cabin, generator cave, and clock tower. Once those are switched up, proceed to the library, the large, rectangular stone building next to the planetarium. Inside, you'll find some pictures, a map, a fireplace, and a bookcase. Look for books that aren't charred, and read them carefully...
The Ages of Myst may be accessed in any order you choose.
Note the map of Myst island in the library. Have you examined it closely?
SOLUTION
Found the power yet? The clue is 7,2,4. Enter the clue in the safe in the cabin and it will unlock, revealing a matchbox. Open it, pull out a match, and strike it on the side of the box. Turn around and hold the match on the small lighter on the bottom left of the furnace.
Make sure the marker switch at the sunken gears near the dock is turned up. Go to the library and set the tower rotation on the map to the gears. Click the painting to the left of the bookcase to open the passageway, go through to the elevator, and up to find your clue.
Inside the clock tower is a machine with two levers and three rows of numbers. The correct combination of numbers will open the gears on the other end of the island. Did you write down the other numbers from the tower? Pull the levers inside to get the combination. A little practice should get it easy.
SOLUTION
Head back across the island to the sunken gears. Inside you'll find the Mechanical Age linking book.
Have you turned up the marker switch at the spaceship and gotten its clue? Have you looked through Atrus's Selenetic Age journal? There's something important in there you'll need.

Notice the two towers between the generator and the spaceship? If you charge the power over 59 volts, you'll have to go to both of them and flip the switches at the top to reset the generator, then return to the generator building and try again.
Once the generator is powered to 59 volts, go to the spaceship and open the door. To your right you'll find the keyboard. To your left, you'll see a machine with five sliding levers. Move each lever and you'll hear a different pitch.
Here is the keyboard diagram from Atrus's Selenetic journal:

At the keyboard, press down the key numbered 1. Let the sound sink into your mind....
Now go to the bars, and mimic the sound with the first lever. You'll need to do this with each key and lever. The settings will be as shown below, though you will need to listen to the sounds and do it by ear to get it right. When you think you have achieved the correct settings, click the switch to the right. If nothing shows up in the glass bubble above the bars, try setting them again. Keep at it!

When you arrive in Stoneship, turn left (in realMyst, turn right) and go over the boards to the umbrella. Under the umbrella are three buttons:
First, you need to explore the brother's bedrooms to find a page (whichever you choose), so click the middle button. The first doorway on your left (from the umbrella) leads to Sirrus's room. To go to Achenar's room go over the stone steps on the ship and go through the second opening on the left.
You can easily find the brother's pages—Sirrus's page is in his bottom drawer, and Achenar's page is on his bed.
The Myst linking book is down inside the ship. To see it though, you'll need some light. To get light, you need power. Where could you get power?
Have you looked in the lighthouse? Notice the basement is flooded and a trapdoor above you is locked. You need to get up through the trapdoor. Go back to the switches under the umbrella and click the right button to drain the lighthouse.
Go to the lighthouse and go down the stairs. There you'll find a chest, filled with water. Inside the chest is the key to the lock upstairs, but the key to the chest is bolted to the floor upstairs. Ideas?
In the top of the lighthouse, you'll find an old-fashioned generator. Click the crank to power it up. Once it's all the way to the top, the generator will power up the lights in the two tunnels. Go back down, exit the lighthouse and go down one of the two tunnels, looking for a secret door (on the lower sides of the tunnel).

Once you've clicked the right button, go back up through the tunnel, and back to the buttons under the umbrella. Click the left button. Go back to the ship, and go down the steps. Open the door. The inside is now illuminated! Make sure you have the page you want, and go down to the small table. Click the top of the table, and the Myst book will bizarrely materialize from the wood.
Once you're back in the Myst library, add your page to it's respective book.
On arrival, after taking a momement to observe the tree-filled view, turn around, and follow the wooden walkway to the windmill.
Go up the rocky island path and step inside the wooden structure. It is important to know first that water is Channelwood's main power source. Click the red lever on the machine to your left, and the valve in front of the huge water tank. This will get the water flowing.
Here on the second level is another elevator that will lift you to a third level—where you'll find Sirrus and Achenar's rooms. However, you need to send power to that elevator, so how can you power two elevators at once? You can't.
You can find Sirrus's page in a drawer in his writing desk. Achenar's page can be easily found next to his message-recorder in his bedroom.
Time to go home. Go back down to the first level (down the elevator, down the staircase). Did you notice another elevator at the far end of the forest?
Now, go past the elevator, and you'll find a hand-turned crank. Turn the crank, and a pipe will extend to the other side. Now you can flow the water directly to the elevator.
Mechanical is a small Age, and it's quite easy to find the brother's pages. You'll arrive on a small island. Walk over to the huge fortress you see ahead. Inside the doorway you'll find two hallways.
The left hallway is Sirrus's throne room, where you will see more of his accumulated riches. You'll find his page behind a panel in the wall next to his throne. It will be inside a box of gold coins. On the wine rack across the small room, you'll find a rolled up note from Achenar to Sirrus, complaining about "[Sirrus's] new tax" recently forced on Achenar's servants.
The right hallway is Achenar's throne room, where you will see more of his weapons and poisons, evidence of his violent, demented nature. Achenar's page will be behind a panel to the right of his throne, as well.
You have your page? Good. Now...how to get home?
Did you notice anything different in Achenar's room? There you'll find a fortress rotation simulator. Play with it for a minute and notice how long it takes to hold the lever to turn the fortress. If this is the simulator, where are the real controls?
In case you happen to lose the correct symbols you sketched out (or perhaps you've been having a fit with the controls and are ready to leave), here is the combination to unlock the Myst book.

Selenetic is a hot and mostly barren world. Look out of the spaceship door and you'll be greeted a dirt path. The first thing you'll notice is a door set into the earth on your right. For now, it's locked, but you'll be back later. For now take time to explore the island and look for the brother's pages.
As you explore, you'll notice a microphone, symbol, and button in important areas, each with their own distinct sound. Click the buttons to turn on the microphones.
You'll find Sirrus's page at the end of the Stone Forest, a cluster of tall, spiky stone pillars on the water with a walkway going through them. To find Achenar's page, go to the Oasis, a small wooded area with a small pool at the end of it. The page lies by the pool. Remember you can take only one page per trip.
Sounds are the key in Selenetic. Have you found all the microphones and turned them on? Did you notice the tower with dishes all over it out in the bay? Follow the narrow path past the Stone Forest to reach the tunnel that leads to it. The control tower... (CONTINUE CONTENT)
SPOILER: The correct order of sounds can be found by moving the levers to the positions shown below.

Click the button on the pannel and the sounds will play back to you. The correct configuration will open the door. Inside, down the stairs, you will find the Maze Runner. Click the button by the door to open it, then enter. The controls are fairly simple. The puzzle, however, is is not.
This is probably the most difficult puzzle you'll have encountered. If it's becoming a bit too much for you, here is the answer.
SOLUTION
Direct the maze runner N, W, N, E, E, S, S, W, SW, W, NW, NE, N, and SE.
Once you link back into the Myst library, take your red or blue page to it's respective book. By now you should've added one page from each age to one of the books. Opening that book should provide you some very helpful information from one of the brothers. Sirrus or Achenar will instruct you to copy a certain pattern from the code book on the bookshelf. Using this pattern inside the fireplace will give you access to three important items—the final red and blue pages, and another linking book. You now have a choice to make.
SOLUTION
The missing page to Atrus's Myst linking book is down by the dock, inside the marker switch. Flip the switch, take the page, and return to the fireplace. Open the green linking book, and enter K'veer...
Sirrus and Achenar not only burnt many of their father's precious links to worlds he had carefully crafted over the years, they were responsible for their father and mother's seperate imprisonments. They lied to Catherine, saying Atrus had gone to Riven. They lied to Atrus, saying Catherine was in D'ni. Both were left stranded, and Sirrus and Achenar began their destruction and pillaging. It's up to you to help resolve the dilemma, and right old wrongs.
(This section pertains only to realMYST)
Once you return from K'veer island, note that Atrus not only destroyed the red and blue linking books, but he dropped a plum-colored journal on the library floor. Time to read.
Once you've linked into Rime, turn around and go up to the hut. Inside, you'll find a book back to Myst, and another door, but it seems to be frozen shut! Just outside the hut, you'll find a switch to turn on the stove inside. Go back inside and shut the door. After having a few minutes to warm up, the room will thaw and you can open the second door. At the end of the passage, you'll find an elevator. Hop in and go up. There you'll find a machine that generates different light shows in the sky—just another one of Atrus' amazing inventions. Back inside the elevator, click the red button to circle around and access another small writing room, with one last journal of Atrus that will tie together some more of the story.
The adventure continues in Riven: The Sequel to Myst.