Well, yes, there are some folks who use the books or the copied lyrics overmuch and do not take the time to learn them. Most, though, in the sing arounds and song swapping groups I know do not rely on the books overmuch, so I say give the printed page people a shot. Those of us who actually get paid to have this kind of fun enjoy the relaxed atmosphere once in a while.

A second (or third) - perhaps fifth if you fiddle - to Art Thieme's suggestion of "Song Fest" It's a gem. Also, if you're into historical songs, I recommend "A Ballad of America" by John Anthon Scott and John Wardlaw Scott, published by Folksong in the Classroom. Tons of songs, spiral bound and good commentary.