Jamil's yeast pitching calculator. http://www.mrmalty.com/calc/calc.html
 

Beer Judge Certification Program (BJCP)  http://www.bjcp.org/index.php

American Homebrewers Association http://www.homebrewersassociation.org/
 
 
Great article on homebrew off flavors http://morebeer.com/content/homebrew-off-flavors