Britannica School Edition for Middle School or High School: Offers encyclopedias and related materials for students.
Explora Teens: Contains middle and high school-appropriate magazine, journal, and encyclopedia articles and also includes primary source documents, reference books, and multimedia.
Grzimek's Student Animal Life: Profiles of animals found all over the world aimed at middle and high school audiences. Includes lists species by biome and geographic range. Get to all the volumes using the drop down list on the right hand side of the Table of Contents Page.
Science Reference Center: An easy-to-use search for student's science research needs. For science fair help click on "Science Experiments" under the Reference Shelf on the right.