Links
Art of Problem Solving (AOPS) Website
This is a very useful website, created by the writers of The Art of Problem Solving, a wonderful book on mathematics for high school students .
Math Reasoning
This is Vern Williams' official site, with information on his math enrichment program and teaching philosophy.
Eric Wiesstien's World of Math
The largest mathematics resource I have as of yet found on the web; useful if you're looking for information on tribbonacci numbers or something to do with abstract algebra. You're a smarty pants if you can read and understand this page.
AMC Website
This is the official website for the AMC 8, AMC 10, AMC 12, AIME, and USAMO contests.
Kalva Math Problems
One of the largest resouces of mathematical problems on the web, this site includes about 4,100 contest problems from the IMO, USAMO, and dozens of regional olympiads. Many problems also have a link to the solution.
