My friends get together once a year for a week and we jam/sing along every evening. We have been using the book "Rise Up Singing" since it lists quite a few song lyrics with chords and almost everyone of us has a copy.
I usually go with an neutral rock or 3/4 beat or somethings standard depending on the song. If you check the PSR2000 tutorial pages you will see under the Music Finder section lists of songs and peoples' preferred styles and tempo.
Hope that helps.

- Brian