Ask Dr. Math (http://mathforum.org/dr.math/ ) – If you have a math question of any level, this is the place to get the answer!
Biotech ( http://biotech.icmb.utexas.edu/pages/scitools.html ) – Biotech was developed by the University of Texas and contains information on biochemistry, molecular biology and genetics, general chemistry, and anatomy.
Cells Alive! (http://www.cellsalive.com/ ) – Everything you ever wanted to know about cells, all in one place. Includes info on cells, microbiology, and immunology. Check out the great animation of cell mitosis and meiosis.
Computer Science Tutorials and Applets (http://www.cs.usask.ca/content/resources/csconcepts/index.html ) – Find all the technical explanations you need on this site from the University of Saskatchewan. Learn about things like Boolean algebra, SQL, trees, and how encryption works.
FactMonster Homework Center: Mathematics (http://www.factmonster.com/homework/hwmath.html ) – Conversion calculator, formulas and more.
General Chemistry Online http://antoine.frostburg.edu/chem/senese/101/index.shtml ) – General Chemistry Online from Frostburg State University provides interactive chemistry help with compounds, reactions, and even quizzes to test your knowledge.
HighWire Press Stanford University (http://highwire.stanford.edu/ ) – Find peer reviewed articles on diverse topics: biology, chemistry, environmental science, and more.
HippoCampus (http://www.hippocampus.org/ ) – HippoCampus provides high school and college students with multimedia help on a variety of science and math topics. Having trouble understanding your physics lesson? Watch a video demonstration on HippoCampus for a different take on the subject.
The Physics Classroom Tutorial (http://www.glenbrook.k12.il.us/gbssci/Phys/Class/BBoard.html ) Find clear explanations of concepts in physics and help with problem-solving and experiments.
PLoS Biology (http://biology.plosjournals.org/ ) – Access abstracts and full research articles from this peer-reviewed journal published by the Public Library of Science (PLoS). PLoS is a nonprofit organization of scientists and physicians committed to making the world’s scientific and medical literature a public resource.
Science Daily (http://www.sciencedaily.com/ ) – An online magazine featuring quick takes on the latest research on a wide variety of science topics.
WebMath (http://www.webmath.com/ ) – WebMath covers K-8 math, general math, Algebra, Trig & Calculus, etc, and doesn’t only give the answer but shows how to arrive at it. Also has conversion calculators, personal finance math, and “everyday math”.