Go up to the person at the cash register and ask (politely) to speak to a manager. Fast food places will almost always have at least one manager on duty. This is a great advantage over just handing a cashier your resume - chances are, your resume will never make it to a manager
Ask them if they are hiring at the moment. If they say yes, hand them a resume and ask them if there is an additional application to fill out. If there is, fill it out in the store and hand it back to them (so make sure you go with the names and phone numbers of references, and any other info you might need).
I've worked for a fast food store as well as retail stores through high school, and I'd have to say the retail store experience was
much better (although the fast food place did pay more.)
Sometimes they will interview you on the spot - this really depends on how desperately they are looking for people. If they do, just be professional and courteous. Make sure you're at least a little prepared for the interviews. They will most likely ask you about your strengths, weaknesses, and to describe yourself - have answers for these generally formed...don't sound like your reciting from memory, though.
Google for more interview tips
University of Waterloo '13
Electrical Engineering
