I've been doing Pilates for a little while. It is primarily a "core strengthener" but there is some leg and arm work too. It tightens and tones you all over without adding bulk. Some of the exercises are odd (really odd!), but they work. I've been fighting a battle with a low back problem for 2 years, Pilates has helped it.
I only do the mat work and I suspect that's what your interested in if you want to do it at home. The best tape I've found for home use is by "Living Arts" and the instructor's name is Ana Caban. (I currently own 9 different Pilates tapes, but her's are the only ones I use! I'm a videotape addict.) They have a beginner and an intermediate mat work tape as well. Do not waste money on the body band nor the fitness ring workouts. They're not traditional Pilates, anyway.
One thing about Pilates, it can be really easy to cheat and do it with less than perfect form. You will not see many benefits from it if your form isn't good. I worked with videos at home before I ever went to a live class. When I worked with the videos, I was "appearing" to do the advanced version of most everything. When I had a trained instructor watching me, my form wasn't so great. When she corrected me and I did the exercises the way they were meant to be done, I found I was down to the most modified version of every exercise -- and I've been an aerobics instructor for 15 years -- boy was my face red.
I went through a course with the Physicalmind Institute to learn how to teach mat classes and I've been teaching Pilates mat classes since Labor Day. The people who have been to class either really, really love it or they really, really hate it. If you spend $20 on a tape and find that you're gonna like it, seek out a trained Pilates instructor and either attend a group mat class or get a few private sessions. You'll have a much more effective home workout after you've gotten a few pointers.