Biology Online is a choice source for biological information, ideal for homework, research projects and general interest.
You can find here tutorials, references, an online dictionary of biology terms and a biology forum.
The Biology Project is an interactive online resource for learning biology developed at The University of Arizona. The Biology Project is fun, richly illustrated, and tested on 1000s of students. It has been designed for biology students at the college level, but is useful for high school students, medical students, physicians, science writers, and all types of interested people. Teachers can assign problems sets for reviews before exams, or may want to assign an activity before students cover that topic in their laboratory. Students will find that the information covered in The Biology Project is probably just what they've been studying in their introductory biology course, and advanced students will find these materials to be a useful review. All students will benefit from the real-life applications of biology and the inclusion of up-to-date research findings.
Modified lecture outlines Michael J. Farabee, Ph.D had developed over many years of teaching college-level introductory biology. A treasure trove of Biology books on-line.
The U.S. Geological Survey provides scientific information intended to help educate the public about natural resources, natural hazards, geospatial data, and issues that affect our quality of life.