Here are some recommendations to get you started:
1) Drop junk mail in the recycling bin on your way in from the mailbox. If it doesn't comes into your house, it never has a chance to clutter up your space.
2) Deal with all remaining mail and other paperwork right away. If this isn't possible, have a basket or dedicated space for storing it until you have a few minutes to deal with it (strewn haphazardly on your kitchen counter does not count as a dedicated space!)
3) As you go through mail and school papers, make specific piles - 'recycling', 'shred', 'action-needed', and 'to file'. Immediately place the recycling pile in the recycling bin, the shred pile in your shred box (or straight into the shredder if you have one), and file papers that need to be filed.
4) For the 'action-needed' pile, deal with as many items as you can right away and keep the rest in a dedicated place (try a file folder or basket) to take care of later. This is a good time to look through your 'action needed' items to make sure nothing there from previous days has been forgotten.
The key to keeping on top of paperwork is to deal with it regularly and consistently. If you have paperwork everywhere and no system for addressing it, it will seem overwhelming, you will avoid doing anything with it, and the cycle will continue.
If your paperwork has been out of control for awhile, and you need someone to help you sort it all out, I'd be happy to help! You can contact me at firstname.lastname@example.org.