Good resources for bee identification include InsectIdentification.org, TheBeeGuy.com and BuzzAboutBees.net. InsectIdentification.org contains information and images of bees, wasps and hornets to help visitors identify types of bees.
Information about bee identification and control is found at TheBeeGuy.com. Due to the pest control angle of the website, TheBeeGuy.com offers more information about the stinging behavior of different bees, including how many times the bee can sting before it dies.
BuzzAboutBees.net contains close-up images of a wide variety of bees, and each photo is accompanied by descriptions of what is unique for these bees. This website also gives a general guideline for bee identification that includes behavior and pollen collection.