Or you could hit up ReplacementDocs, I reckon
If you've got a ton of Nintendo games just laying around without manuals and there are no gamer yard sales around to pillage, Nintendo has just the answer. The online store is selling a bevy of replacement manuals for games like Banjo Kazooie, Duck Hunt, Final Fantasy Tactics Advance, and more. They run the gamut from $1 to $2, but word on the street is you don't actually get a pristine manual -- you get a laser-printed facsimile.
For all that trouble, you could just hit up a PDF online and print them out yourself. Still, it's an interesting service that Nintendo is providing, even if there is a random assortment of games. Wave Race 64? StarCraft 64? Weird.