Everything that bimjob said. BUT make sure you hand it in to the manager as well. If it's for a shop or something make sure you hand it to the manager. If you give it to the workers they might just bin it - I know people who've done this. If you think about it, they don't want new people applying and possibly replacing them in a job. If they don't hand it in then they're safe.. So hand it to the manager. This also gives the opportunity for you to meet the manager, say hi, maybe have a little chat. It makes your application more personal and real and so much more highly valued than any other anonymous applicant. Good Luck :)
Just give it to the person you got it from, and they will give it to the manager. You don't have to say anything to impress them when turning in the application. But if they don't call you within a few days, call them and make sure they got the application, and ask if they're hiring.. This shows that you are interested in working for them.
When you go to a place to get a job, make sure you are dressed neatly and appropriately, have a pen to fill out the form and a sheet with details like phone numbers and addresses you might have to fill out (It shows that you are prepared and serious about finding a job). Thank them when you turn in the form. Be polite. Good Luck!!
Just hand it to one of the works and say, "I filled this out, I'm not sure where you'd like it."