Once Accepted into college/ university or trade school there will be a flood of paperwork coming at you. A lot of it will probably be online while other stuff will come in the mail. Do not let it overwhelm you, just stay organized and take things as they come. I suggest a binder with dividers or an expandable wallet, letter (these are water proof and already have gaussets for separation). You can get them at staples or wal mart. Keep records of everything just in case! When you submit something print out the summary pages and the proof of submission pages, you can never be too prepared in college. Print off contracts and invoices from payments. Once I started school I even put school reciepts (like book purchases, returns) in the college binder so if there was any discrepencies I had proof. File all of this stuff. You can organize it however you want. I did it by finances (financial aid, bills, reciepts), housing (contracts, requests, assignments), and academics (book lists, schedules, book reciepts from purchases or returns). I would even keep a calendar or planner or even just type up and put a list in the front of the binder of when everthing is due. Stay on top of everything, dont let anything sneak up on you.
It's also a good idea to have another binder or expandable letter for copies of personal documents (such as voting registration card) if you are going to be far from home with little access to them otherwise, but do not leave this lying about. I know someone who opted to by a safe but I don't have that much money and I don't live that far from home so I just keep it put away and take it home when I go.