WEll, everything's already been covered pretty well. I would suggest though, that if your serious about improving hang around on the forums. It'll give you the chance to picjk the brains of some excellent painters and helpful teachers. The Submissions, Paining & Cinversion, and the WOrk in Progress Forums are all great sources of information. Genereal Discussion is also a great source; it's just that nobody's quite sure of what :-) WHile CMON is itself great, I think it's the Forums that really make it a marvellous resource.
And remember, its not unheard of for winners of local painting contests to get in the 5 to 6 range on CMON. DOn't let teh scores get you down.