In terms of equipment, probably a speedlite would be good (flash that goes in the hotshoe on top of the camera), they tend to provide better photos than the little popup one on the camera. For a single lens, I've heard some fairly good things about the 17-55mm, although I've never used it. Alternatively I have used the older Sigma 17-70mm and thought it was pretty good, the newer version is supposed to be better and have some image stabilization technology in it.
In terms of software, DPP is pretty good for provided software. Otherwise, the main software is Lightroom or Aperture (Mac only), with a couple of smaller and lesser known software packages out there. I've never used Aperture, but I wouldn't say Lightroom is immediately easy to use, although I got the basics of it down fairly quickly. If you want to go beyond the iPhoto type use, you likely will need to do a combination of online tutorials, classes, and just plain messing around with the settings on different photos to see what happens. Both of those software packages are quite powerful, combining both DAM (digital asset management, e.g. catalog/tagging/etc) and general global photo editing.
DPP, as I said, is pretty good, especially for it coming with the camera. It will let you do pretty much the same kind of things that Lightroom/Aperture can do, although it's a different interface and is more about the photo you're looking at, rather than providing much in the way of DAM. Whatever software you go for, I'd highly recommend taking a workshop class in basic photography and basic editing at your local camera store/continuing adult education place. Those will likely help you a lot in understanding some of the underlying terms and concepts, and often you can use online tutorials and forums for a lot more.