20-30 ppl interview at certain time intervals by filling out application and speaking with one of the hiring personnel at which time they offer you a position that you must sign off on stating you will be offered this position as long as you pass background check and drug screen.

Very simple. Show up take ID picture, pass drug test(I think) and nothing else to it. There's usually a long line of people when you show up but that's not normal, Amazon hires in batches.