http://www.artofproblemsolving.com/Forum/resources.php http://www.artofproblemsolving.com/Forum/resources.php is a good source of problems. I'd just stick with

http://www.artofproblemsolving.com/Forum/resources.php http://www.artofproblemsolving.com/Forum/resources.php is a good source of problems. I'd just stick with USAMOs (click on the "USA" link), they're varied and of pretty high quality.