Resources

UVA ACM Problem Set Archive - an online problem set with online judge.You must register to be able to submit to the online judge. Also, UVA only has good support for C++

UVA Online Forum - use this to find problems of a specific type for UVA

TopCoder Arena - an online programming competition. Also has lots of good tutorial (look for algorithm tutorial on the side bar under educational content).

CPP Reference

Cplusplus Resources

Java API

Newsgroup: ubc.courses.cpsc.490

How to find Problems

In UVA

In TopCoder