You know what is really weird about this 'new me'? Two years ago, before I started this drive to lose weight, I would have sworn up, down, sideways and inside and out, that I was not using my weight as an excuse. I had several friends confide in me that they were really glad that I seemed happy with my weight and seemed to be a confident, happy person.
My weight loss didn't even start out with a 'mental attitude adjustment' element to it. But once I lost the first 10 pounds, I noticed I was more active and more positive. 5 more pounds and I signed up for belly dance lessons. 10 pounds more gone and I am *stunned* at how I feel about myself. I feel like some corny infomercial that vows it 'will change your life'.
About bellydancing DVDs - Pretty well any DVD is good for learning a thing or two, so use what you have. There are many difeerent styles of belly dance, and the different DVDs reflect that. What style I like may be quite different than whay you end up liking, so try whatever you can get and see where they take you! These are a couple of well recommended belly dance DVDs that are good for newbie basics:
Bellydance Basics and Beyond by Jenna
Bellydance for Core Fitness by Ayshe
But - the best thing is to find a local class if you can afford it. The instructor will be able to correct your posture and technique, and inspire you to do more and better. I don't know how comon it is to find 'plus size positive' teachers and classes out there, but based on some of the belly dance forums I have read, being fat is *not* a problem. Most teachers are more than happy to teach to all sizes. Size is no bar to belly dancing. Some movements look better when you're whip thin, others look better with a few extra pounds, and some look best on heavier women. My teacher is thin and supple, but is so very encouraging to me and a couple of other heavier women in the class that no one feel self conscious at all! And now that I can shimmy, boy, does it look better on me than on the stick thin girls!

If dancing is in your blood, then go for it, and don't allow worry about what other people might think stop you. Remember - you are not doing this for others, you are doing this for *YOURSELF*. This is your life to have fun with, so go do it!!!!
BP