Skinning (at least in RR) is pretty easy. No previous experience with programming needed. .skin files are just text files that specify what graphic is where, and what action it performs when you click it. Everything you need to know is in the included readme, and will just require a bit of reading.
If you want to customize the look too, you'll need a graphics program like PhotoShop or PaintShop Pro. The skins are basically .JPG's and .skin's. That's it. If you have an XP machine you can play with, I recommend downloading a copy of RR, and playing with the skin. It's the only way you'll learn it.
Oh, and you can always do a beta system for pretty cheap before really investing a lot. Check the classifieds in here for good deals on used equipment. In fact, I've got two spare "Book-PC's" w/ P3's, one 566Mhz, the other 900MHz that would just need a monitor (biggest cost), keyboard/mouse (use full size temporarily to save $), and PSU (again-used for well under $100). PM me if you're interested in looking at one of my spares.