Online or applying in store
Apply online. Apply online. Apply online. Do not come into the store with a paper copy of your resume. If you DO come into the store, ask to speak to the manager on duty, politely introduce yourself, and give them your resume. Absolutely under no circumstance apply in store with your friends/significant other/parent hanging around you, and NEVER apply in a group. That's an automatic no. Dress the part, don't come in decked out in Aeropostal.
You ask to speak to the hiring manager, hand them your resume, tell them a little about yourself, and wait for a call back.