i dont have any good books... but i know alot of good people / places you can check out ..... some of the decent ones are
www.dpreview.com or
www.dgrin.com which is run by smugmug .... or
www.Nikoncafe.com i talk alot there and there are many people who are professionals there that can help you with whatever questions you have about learning or going up to the next level with your work ... !! If you need some advise or some
just shoot me a PM or hit me up on the IM
good luck !!
---Topher
Tucson Sports Photography
www.TucsonSports.biz