HELP Which program to use?

I'm not new to photography, or to digital photography, but I'm getting more interested in post processing. I have a few programs given to my by the wife of a friend of mine that passed last year, including PhotoShop CS3, Lightroom, Elements 5.0, and Photo Studio 5.5. Currently I have been using DPP that came with my camera just to do overall sharpening, some color adjustment, and highlighting, but find it very restrictive. I know that PhotoShop is used by most, with Lightroom becoming popular. Of the programs listed, which is the better program? As I do not have a lot of knowlege of the programs, what books would you recomend that would be easy to follow for post processing with the programs? Also I need something so windows can see the Raw files from the Canon 40D.

Photoshop CS3 and Lightroom will be all you need (although they do different things). As for learning, good bookshops are full of books on PS - or you will find heaps of advice on the net.

^ What does Lightroom do that Photoshop can't?

It is much easier to sort, convert, label and, to an extent, modify digital files in Lightroom - all in a non-destructive way. It excels as a file management system.It probably can't do anything that Photoshop does, it just does it quicker and easier. What can a computer do that a human being can't?