I have gotten rid of nearly all my instructions booklets that come with appliances. I found I could get them online if it was needed. I keep receipts after checking them off on my credit card bill only if it is something I might return. Grocery, restaurants, hotel stays and pest control services, I can obviously get rid of. Anything with personal information or credit card numbers gets shredded. I then use the shredded paper as packing material when I send something in the mail that might otherwise get broken.
If I am not sure if I should get rid of something, I ask myself how tough it would be to replace it. If it is something I could get online, like last month's bank statement, ditch it. Out of date maps and travel info gets ditched. Work through your pile and get rid of as much as you can. That way when it gets put away in files, you will know where to access it ...and it may be one of several in a file rather than one among hundreds!!!