Ack! My arms, my arms!
 

I'm doing pretty well, having lost a few inches from my thighs, hips, waist... but my upper arms, specifically the backs of my upper arms (what are those muscles called?) are so jiggly. I lift my 2 lb weights, till all the other parts of my arms are burning and I can feel that I have worked them- even the bicep-but nothing I do seems to get to this spot. I'd be ever so obliged if somebody knew of even just one exercise that can reach this area.
Thanks!
F.

I think the muscles that you are refferring to are the triceps. To work them out you can do a few types of workouts. One that I would recommend because of its simplicity would be to use a single dumbell of any weight you are comfortable with. Grab one of the weighted ends with both of your hands and raise it behind your head. Keep your elbows in the some position while bringing your arms up to lift the weight and then slowly back down behind your head. Keep this up for about 8-12 reps per set and you should feel the tricept area getting a workout.

It sounds like you need a good upper body strength training video that will utilize all of the muscles in the upper body-and actually explain each muscle area and what exercise helps that.

A great video for the upper body with lots of tricep work:

I Want Those Arms! (Tamilee Webb is the instructor)

You might also want to increase your weights to a higher set as the exercises get easier. You should get past 2 pound weights pretty quickly and move on up to 3, 4, and 5's. 4 pound weights are hard to find-I found some at TJ Maxx recently.

You really want to progress with your weights to get firmer and more definition in the upper body. Women can't bulk up and get huge like men-we don't have the testosterone to do so-I use 4-15 pound weights depending on the muscle I am working. You want to keep increasing the weight to get better results. You will notice that your shoulders and biceps develop quickly-but your triceps will take a little longer to develop-but it is worth it when it does.

Some other good upper body videos with triceps work:

Hit The Spot-Arms & Bust-Denise Austin
Shorcuts-Upper Body-Leslie Sansone
Getting In Shape With Weights For Dummies-(this is a full body workout, but is great because it explains what each exercise is for-your shoulders, back, biceps, triceps, etc.)