I read a review of my first camera (*ist DS) that trashed its JPEG conversions but liked everything else. So I shot RAW from the start, except for some shots that showed the review was not wrong.
For software, I primarily used Adobe Photoshop Elements. If the shot is good, it's all you need. Its interface makes sense to me. It also gives you some background if you ever decide to move up to another Adobe product. They all use a version of the Adobe Camera RAW converter. It sounds clunky at first to open up a separate program first, but it works well in practice. Elements has limited features in its RAW converter version and editor but the limits don't get in the way, unless you are moving a tree from one photo to another, and coloring each leaf to simulate fall.
Pentax's software can do a lot but its interface is designed to hide all this from you. Maybe not on purpose but that's how it works. It's like reading your camera manual in a foreign language.
I have used Photoshop CS5 and it is about ten times more complex than I ever need. But I do like some things over Elements. The Organizer part of Elements is really inflexible for browsing through images. It can't be rearranged very much, and can't show as much information up front. It's geared more for face tagging than seeing which focal length I used. CS5 can also do much more with groups of photos, like applying the same white balance. It takes advantage of multiple monitors. There may be a button for adding fall foliage.
Now, I don't care how good it is, I wouldn't pay its full retail price, because I'd feel like I wasn't getting my money's worth unless I spent hours processing each photo. My wife gets an academic discount and has a use for CS5, so we're going to buy it shortly.
I think I could get by with Lightroom. I borrowed this highly recommended book for CS5, "The Adobe Photoshop CS5 Book for Digital Photographers" by Scott Kelby. At least a third, maybe even half, is about using the upgraded version of Adobe Camera RAW that comes with CS5 and Lightroom. As I understand it, Lightroom has a great interface for organizing photos and uses Camera RAW for editing. It sounds like exactly what I'd do.