Best thing about Pilates is that you can "grow into it". If you stink at first (and I did) just keep plugging away, doing the poses correctly and to the best of your ability. You will find that you get stronger and more flexible if you're committed to it and do it at least three times a week.
My fiance and I do one with resistance bands (we've been going at it for a while) that help to enhance the workout (make it harder).
Good luck everyone! This is the best exercise that I have found in a while. It's something that I actually look forward to doing!