American Association for the Advancement of Science Evolution Resources (links to diverse views, including atheistic, some theistic evolution, non-overlapping)

Skeptical Creationism Web site. This site has the most references to other sites of any that I have seen on this topic, and not only those promoting the views of the author.

American Scientific Affiliation. For the most part, the members of this organization are not young-earth creationists, although some are. The organization attempts to consider all points of view on origins compatible with Christianity. (It publishes many articles on topics other than origins.) They do believe in God's creative activity. See the Topic Collections for on-line articles.
Some important articles from this source are as follows:
"Radiometric Dating: A Christian Perspective," originally published in Perspectives on Science and Christian Faith, in  1994, is, they say, the article most downloaded from their site.
"Theological Implications of an Evolving Creation," by Keith Miller, argues that "God is continuously active in His creation through the processes that we investigate with our sciences."
"The Mediterranean Flood," by Glenn Morton, proposes, giving scriptural and scientific analysis, that Noah's flood was a flooding of the Mediterranean basin, not world-wide.
"Making Sense of Genesis 1," by Rikki Watts, argues that much of Genesis 1 was not meant to be taken literally.
"How Long Were the Days of Genesis," by Thomas Key, argues, from scriptural evidence, that the days of Genesis 1 could not have been 24-hour days.
Two articles by Conrad Hyers, a religion professor, on the proper interpretation of the text of the first parts of Genesis. Part One, "Dinosaur Religion . . .," and Part Two, "The Narrative Form of Genesis 1 . . ."
The American Scientific Affiliation has been granted permission to post "Because It Had Not Rained," an article by a seminary professor, which argues that a strictly literal interpretation of the Genesis 1 and 2 is not possible, based on the scripture itself.

Reasons to Believe is a progressive creationist organization. To see what their views are, go to their FAQ page.

Theistic Evolution -- One Christian's Perspective is a page presenting an old-earth creationist view. The author has also created a particularly interesting page giving internet references to pertinent information. He majors in showing how young-earth creationists have, too often, misquoted or misinterpreted.

Science and Creationism: A View from the National Academy of Science. Mostly atheistic.

Creation Research Society. Young-Earth creationism.

Position papers, pro and con, on Intelligent Design, published in the May, 02, issue of Natural History, with links.

Institute for Creation Research. Young-Earth creationism. See, in particular, the Tenets of Creationism by Henry Morris, the founder.

PBS's Faith and Reason. See especially the Cosmology and Evolution pages. Atheistic.

University of California at Berkeley's page on Understanding Evolution. On the face of it, atheistic, but has a "misconceptions" section. One such page says that "Science does try to investigate how life started . . . but these considerations are not the central focus of evolutionary theory."