Legal and ethical aspects of making a mix-tape?

My synagogue is having an auction to make money for its operations. We are all encouraged to donate items or services for people to bid on. I wanted to make something homemade. One of my specialties is making mix-cd’s for friends. When I rip songs from cd’s and put them on gift compilation cd’s for my friends, I don’t worry about copywright and such. If people would be paying money to buy raffle tickets or to bid on my cd’s, then what are the legal and ethical considerations that I should be thinking about? Would I need to get permission from the artists for the use of their music, for example? Thanks!