Go to your local Kinkos (or whatever your local print shop calls itself..). Mile has a laminator - in about a minute and $2, I can laminate anything up to 11x14). Trim to suit. It is a good idea to shrink the document size as much as possible before laminating, using the xerox.

Another trick is to just place the sheets in the right sized ziploc bag. That will give them good protection if you are not pulling them out too very often. Ziplocs are available in a wide variety of sizes