Hal Leonard Publishing has developed a pretty decent series of song books designed for worship teams that are thin on talent, musicians or both. The Worship Band Play Alongs are instrument specific and include 8 songs written specifically for your instrument. The Gig Guides are specifically designed for a 4 piece band with vocalist and include sheet music for each instrument. These are great tools for a couple of reasons:
They provide a newly formed group of inexperienced musicians a set which they can practice at home and rehearse together
They provide a great starting point to alter commonly known songs to other musical styles, like when Israel Houghton recorded "Here I AM to Worship" by Tim Hughes in a different style.
Because they all come with demonstration and instrumental tracks, you can use them to fill in for non present instruments, giving a small worship band a fuller sound.
So if you need more of a roadmap to whole your group together and way of keeping everyone "on the same sheet of music" here is an excellent place to start.