That skin issue really is a sucker punch, isn't it? Something that we never anticipated when we started and had visions of bikinis floating through our heads? Believe me, I really feel your pain.
As for bodyfat, did you try having someone caliper you? I had a ton of skin but was still able to get my body fat done that way. But I'm sure a lot depends on the skill and experience of the person doing it. Otherwise, I think you're stuck with bioelectrical impedance devices, like Tanita scales and the Omron hand-held. They read high on me but at least you can track trends over time. But only use it at the same time every day and under the same circumstances because the results will vary wildly depending on your degree of hydration.
HR monitors are great! I tend to get lazy with my cardio unless I can see where my heart rate is and know I need to kick it up. As for weights, I'd suggest three full body workouts a week (like M-W-F or T-Th-Sa), doing 1 - 2 sets of an exercise for each muscle group. There are some stickies in the Ladies Who Lift forum with ideas for beginners. Also check out
http://www.stumptuous.com/cms/index.php - the best site on the Internet for women's weight training.
Mel - the moderator at the LWL forum - can personally attest to the power of weights to reshape your body. She dropped two pants sizes without losing a pound once she started seriously lifting.
