For click-list they usually start at 4 a.m. and close at 8 p.m., so you'll probably be scheduled for a time in between depending on the store. Some stores offer graveyard shifts for click-list. When they ask what hours you want to work be as straight forward as possible. As a student you shouldn't say minimum of 20 hours because that gives them the opportunity for them to schedule you 25 plus hours. They do not offer less than 20 hours of work. The first week of training will usually be close to 35 hours or at least that was what it was for me. After that they weren't very consistent in scheduling.
A wide range depending on what one is looking for. Paid time off, excellent insurance, employee discounts, possible college tuition reimbursement OR programs.