As a general rule, the image needs to be flipped for use with a light transfer. But does NOT need to be flipped with a dark transfer. But be sure to read the rules that come with your transfer paper. This may not be a hard and fast rule.
Most transfers require the use of an inkjet printer. To my knowledge, the printers they use in places like Staples and Kinko's are laser printers. They will not be able to print to a standard inkjet iron on transfer. A laser printer uses far too much heat and could not only ruin the transfer itself but could melt inside their machine.
Also, as an aside, most places will not print Disney or trademarked images because of copyright.
Your best bet is to print the transfers yourself. It is very easy!
