These are some useful web pages for general scientific topics, including biology:
BBC
Science
and
Nature
Nature
magazine
Natural History
magazine
New Scientist
, and the
Lastword
answers to questions
New York Times
science section
(free registration required)
Science
magazine
Science News
Online
Scientific American
magazine
Thinkquest
Science library
Voyages of Understanding and Discovery
The Evergreen State College home page