My son completed his Sophomore (MS2) year on May 14th. He receives his book money between 30 and 40 days after the semester begins. The money is deposited directly into his personal bank account. He purchases used books when available and get some through Amazon at reduced rates, he has yet to spend the entire book money given to him. At the end of the semester he sells what books he can. Any money left over is his to keep which has been quite a bonus. After he sells his books and with the discounts from Amazon over the last 2 years he has only spent about half of the book money and kept the rest. I haven't heard of the bookstore debit system mentioned above but different schools may operate various systems, best to check with them early. The big thing is to be prepared to purchase the books with your own money and then wait for the reimbursement.
At my son's school they do two recorded AFPT's a semester, one at the beginning and one at the end. They have at least one diagnostic test during the semester as well. You will need to pass your AFPT which is given within a week or so of starting school to be able to contract and recieve your scholarship, book, and stipend money. Once you pass you will need to continue to pass you recorded tests, if you fail one they will work with you to get you back in line, but really, if your just passing with the minimum your already below standards so it should not be hard to keep up.
Good luck with your first year, your going to love it.