It seems like I post this recommendation often, but I'll do it again.  I highly recommend Bryan Peterson's excellent book called, "Understanding Exposure: How to Shoot Great Photographs with a Film or Digital Camera (Updated Edition)".  It's easy to understand, and is almost certain to reward you with better photography via creative use of the features of your camera...which you paid handsomely for.

Since acquiring this book, I shoot in full manual or aperture modes 90% of the time.  Truly, exposure is what it's all about.  If one can't grasp the concept of light, exposure, focal length and Depth of Field, then one certainly can't progress into a better photographer.  Learn to trust your camera's meter!

'P' mode should be outlawed :)

http://www.amazon.com/Understanding-Exposure-Photographs-Digital-Updated/dp/0817463003/sr=8-1/qid=1168883443/ref=pd_bbs_sr_1/002-6338668-3571244?ie=UTF8&s=books

Kind Regards,

Steve