Hi, I want to print out some paper money for a cake (loose bills to lay around the cake). What would be the best, frosting sheets or wafer paper? Or something else entirely?? Thank you.

Frosting sheets will look the best. I would use them on top of gumpaste. So, make the gumpaste shape, let it dry, then add the frosting sheet.

Also, be sure to follow the guidelines of printing money: http://www.secretservice.gov/money_illustrations.shtml