Hi, Marna! I'm another lifter who has to deal with fibromyalgia. I've found that the strength training has been very good for it overall, and that a burst of excercise at the start of a flareup can actually help mitigate the flareup (if the flareup has time to sink its teeth into me, forget it).

Gubernatrix has a few articles on body-weight exercise, and I've been meaning to check out this blog after reading a very interesting piece by the author regarding squat form. I have some balance/form issues, and it looks like there's some good reading here--sorry I haven't had a chance to really review it yet.

ExRx.net has a pretty extensive library of exercises, including bodyweight variations that seem to hit every muscle group.