What are major and minor sins and the list of actions that fall under them, what are the types of zina, and is the concept of zina limited only to sexual intercourse between a man and a woman?

A minor sin is every act forbidden by Sharee'ah that is not included in the parameters of a major sin. You can consult Al-Zawaajir by 'Allaamah Al-Haythami and Al-Kabaa'ir by 'Allaamah Al-Dhahabi to see a list of major sins. For a definition of Zina (fornication or adultery) and a warning against it, please refer to Fatwas numbered: (34043), (49467), (63075), (63229), and (46532).