Shooting from the other hip
If you are really new to Pro Tools, are you trying to record an instrument(like guitar, bass, keyboards) to an INSTRUMENT track? Those are for VI(Virtual Instrument) plugins. Guitar, bass, external keyboards and the like should be recorded to AUDIO tracks.
If you have some cash to spend on lessons, groove3.com is a very good deal for(IMHO) the best tutorials available. On a shoestring budget, youtube.com is actually not bad(start off looking at things like "getting started with pro tools"(without the quotes).
