S.T.
Certainly read everything you can get your hands on! This is a great one because it's what is given to the doctor. http://www.fda.gov/cdrh/pdf/P010013c.pdf
I wouldn't have it done because it says in the link above it is not a form of sterilization and information that pregnancy following ablation is VERY dangerous for mother and baby. Given that no form of birth control is 100% I think that's too dangerous a procedure. In the study I'm looking at 3, of the 19 patients had hysterectomies and 1 had a hemorrhage (you can die from that.)
Tubal ligation also (as a PP said) increases the chance of a hysterectomy by a huge amount. For the tubal, one in four women have a hysterectomy fairly soon ( a couple of years) after the procedure. 25% is a lot- and a hysterectomy can cause a lot of other problems.
Unfortunately NovaSure is still too new to know the long term side effects of this brief procedure.
Have you talked to a dr to see if bio-identical hormones might help? I think Oprah tomorrow is going to discuss that. My OBGYN in Houston Dr Del Castillo specialized in this area.