The site that I used for my research on Cain and Abel was essortment.com. I found this site very good because it explains exactly what happened in the Cain and Abel story and uses bible verses as a reference to an interpretation of the story.
The brief summary of the Cain and Abel story:
Cain and Abel were sons of Adam and Eve. Cain’s job in life was to basically take care of the earth and Abeles job was to take care of the flocks (a number of animals of one kind).Cain and Abel had to give a sacrifice to God. Cain’s sacrifice was his job (taking care of the earth) and Abel’s sacrifice was the love for his job (taking care of his flocks). God respected Abel’s offering but did not respect Cain's offering to God. Cain became very angry with God and God warned Cain about his pride and anger. Cain did not listen to God and he reacted to his feeling instead by killing his brother Abel. God later asked Cain where was Abel and Cain responed "I don't know am I my brothers keeper?" God, who already knew what happened wanted to test Cain and see if he would tell the truth, and ask for forgiveness.Cain was punished by everything being taken away fron him (his home and job).