Here are some of my favorite links:
Fairbottom Bobs
Brief History of the Steam Engine
Steam Engines of the Eighteenth Century
Eighteenth century Newcomen model
The Miners Friend
The Newcomen Engine
Steamboat Ed
The Kew Bridge Steam Museum
Fairgrounds, carousels, and many other items of interest, including steam
Paper 'n' Steam Galore
Morrison & Martin Engine Works
The Traction Engine Pages
The Great Toy Steam Company
Industrial Metal Sales