It's a system based on yoga stretching & strengthening poses, but with lots of equipment (balls, straps, blocks). It was developed by joseph pilates as a form of therapy for injured bodies.
There are tons of videos, books, & classes available. Just check out the internet or any local bookstore.
The only way to learn pilates is by taking a class with a good, certified instructor.
I've tried the winsor pilates tapes, well, nice workout, but after my first couple of classes in holland, I realised that there's much moreto pilates than mari winsor teaches you...
I am in a pilates class here in the states now, and this teacher has different techniques.
However, you really need a certified teacher to be doing it right and to get the most benefits.
In my personal training assesment, I scored excellent on flexibility, and thanks to the pilates, my core is in great shape, too.
I purchased the pilates dvd and I liked it at first, but I just wasn't very disciplined with it! I would suggest having a friend do it with you that way you guys can rely on one anther. You only have to do it 3 times a week, but like I said I am not very faithful to it!
I would be very careful with the windsor pilates. I am a certified personal trainer and have several of mari windsors tapes and I am shocked at some of the exercises she does that clearly compromise the back. She has one strength training video out that uses hand weights during abdominal and leg work, which is done way to fast and isnt going to accomplish much accept yanking something in your back. Im sure there are some good classes out there, but check them out carefully.