This is about as far from Library 2.0 as you can get (and perhaps short-lived), but I created a quickie guide for putting books on the shelf according to the Dewey Decimal System.
My library has gotten a few new pages (people who put returned books back on the shelves) and shelf-readers (people who straighten the shelves and make sure the books are actually in order) recently, and when I started training them, found that we had no documentation on the Dewey Decimal System. We had a Dewey test they needed to pass before they were allowed to work, but nothing with which they could prepare for the test.
So I made up the handout below, as a quick overview/introduction to Dewey, and also a reference guide for them to keep with them in the stacks until they get the hang of it. It's designed for double-sided printing, and some of our shelvers even laminated it.
This handout is tailored for the Chelmsford Library, but feel free to modify the Word version to work best for your library. If you have any questions (or notice any mistakes), please let me know.