A few sites for people interested in the study of advanced basketball statistics.  You can also get in the discussion on HoopCoach about applying these statistics to College and High School teams.

• KenPom.com - Certainly the go to guy for college coaches and their assistants
• 82 Games - NBA stats site
• Advanced Basketball Stats 101 - Nice introductory blog post to basic concepts of APBR metrics. 
• APBR Metrics - Great forum to ask questions.  I have hit them up a few times and the responses were thorough and pertinent.  Most importantly they were not condescending.
• Basketball-Reference.com - Database of historical stats
• SonicsCentral Stat Sites - List of other basketball stat sites complete with the statisticians behind them.

Additionally, here is an outstanding paper that was recommended to me by one of the users on SonicsCentral.