Everyone needs a file system. However files that need to be used frequently can live on your desk in something like this. I like that it's flat rather than graduated and has side enclosures. Keep those papers safely tucked in one spot!
A box for each kid K-12 ... I had a professional organizer at my house (what a treat!) and she suggested this system for pictures and papers, etc. 1st year, 1-2, 2-3, 3-4, pre-K, K, 1st grade - 12th. So simple, but so brillant.