For a definitive entry to sites of interest to bio-scientists go to http://www2.auckland.ac.nz/lbr/bio/biometa.htm
A professional site for biologists; includes journal articles and an internal search engine. http://www.biologists.org/
A genetics text, beginning from simplest concepts; includes animations, questions, video clips, audio, photographs, problems and links. This attractive presentation can be viewed at http://vector.cshl.org/dnaftb/
DNA: The Instruction Manual for All Life - a brilliant visual site http://www.thetech.org/exhibits_events/online/genome/
The Genetics Education Centre at Uni of Kansas Medical Centre has a site at http://www.kumc.edu/gec/
The National Human Genome Research Institute has an informative site which includes an extensive glossary of genetic terms; read the meaning of a term, and/or listen to an audio extended explanation. http://www.nhgri.nih.gov/
Evolution and anthropology presented comprehensively at http://www.bbc.co.uk/science/apeman
Learn about the heart from this site. Superficially the site seems to be mostly hyperlinked text with a few diagrams, but there is also a gallery allowing a virtual visit to a real museum exhibit, and you can link to other sites with photographs and photomicrographs giving immense amount of detail on heart and blood vessels both healthy and diseased. Expect your diet to change after you visit http://www.fi.edu/biosci/heart.html
An excellent site about cells including bacteria and viruses, with some animations and movie clips, lots of links for further information and a HotBot search engine. Visual presentation makes it suitable for classroom projection. http://www.cellsalive.com/
Cell City is a study of the cell, likening it to a city. Multimedia, interactive, directed to younger students but including quite advanced concepts. http://www.tela.co.uk/cellcity/
Another site with lots of photomicrographs, including cells and mitosis: http://www.microscopy.fsu.edu/
A simple but beautiful pictorial presentation of development of a child in the womb during pregnancy. Slow, unless you have a fast connection. Girls will love it. http://www.pregnancycalendar.com/first9months/
An American Union of Concerned Scientists have a site dealing with science, innovation, sustainability, green living, health,agriculture, arms control, energy, global resources and transportation. Worth a look, but remember that opinions from a group with a particular agenda need to be balanced with opinions from other sources. http://www.ucsusa.org/
Neuroscience for Kids is a site with an enormous amount of information on the brain. Take a look at http://faculty.washington.edu/chudler/introb.html
A rich source of discussion material presented as "Your Guide to Health Fraud, Quackery, and Intelligent Decisions" is to be found at http://www.quackwatch.com/
Watch this space for more great biology links