Lightroom 3

Since you asked for an "inexpensive" solution you can always start with the FREE Lightroom User Guide: http://help.adobe.com …sing/lightroom_​3_help.pdf

It is very well written and illustrated, and its frequently updated to provide greater clarity.

A stack of various topics on short video clips here---> http://www.jkost.com/l​ightroom.html
I'm just learning it myself and this is very clear explaining what does what and how to use it. Another I've found useful is http://thelightroomlab​.com/category/tutorial​s/

i don't know if you consider $50 inexpensive but i am using these video's
"The Luminous Landscape Guide to Lightroom 3"
8 or 10 hours long but you can watch what parts you are interested in first
i watched sharpening and noise reduction a few times and each time picked up something new

http://www.luminous-landscape.com/videos/l​r3.shtml