Everyone's Called to Youth Ministry (They just don't know it yet.)
Darren Sutton - LeaderTreks
I haven't read the whole thing, but the title and prologue were right on.
LifeTeen is a great resource for all sorts of things, and not just if you subscribe to their program. Here are a couple of links I found that talk about the need to find and train your volunteer ministers:
DYM University is a set of resources from Download Youth Ministry (I talked about them a while ago) that you can use with your team or as people come on to your team at different times. It is not free, but is pretty reasonable for what you get. Plus if you do the overall DYM Membership, you get a further discount.