RAW - Dumb Beginner Questions

I've got a 30D that I use w/ a variety of Canon lenses ( 85, 28-135, 100-300 ) to shoot mostly my daughters travel soccer team & BB team.
I've always shot JPEG, and for the most part, have been happy with it.

But friends of mine have been urging me to try RAW. they teel me the ability to make changes is incredible.

I had tried RAW years ago once with my old S30, and it struck me that, upon opening the file for the first time, the initial file did NOT look very good. OK sure, you had more latitude to make adjustments, but my first thought then was - WHY ?

Now I'm told things are way different with RAW. And all my photographer friends (2) have urged me to try it - and say that once I use it, I'll never go back to JPEG.

So, I'm asking a few dumb beginner questions -

1. Am I better off using Adobe Lightroom 2, iPhoto 9, or Canon DPP ?

2. Should I just shoot in RAW, or is there any reason to use RAW+JPEG ?

3. what area (exposure, wb, etc) does RAW offer the most power to make adjustments ?

4. can anyone share a simple workflow with me - I'm on a MAC

Many thanks,

Dave B