Probably one of the best places for exercise info as it relates to which muscles do what and what exercises work which muscles:
http://www.exrx.net/Exercise.html
http://www.exrx.net/Lists/WtFemale.html - Female exercise map
Triceps: toning these will go a long way to fixing that 'bat wing' problem many of us contend with. Contrary to popular opinion it's the larger tricep muscle that makes the most dramatic change in arm shape, not the bicep.
Kickbacks
Lying Triceps Extension
One armed tricep extensions
Bench dips - if you do these start with feet on the ground, bent at 45 degrees. The further out you put your feet the harder, when you raise them its even harder, and when you put a plate in your lap?
FYI, I could barely manage 4 or 5 of these with legs bent when I started, they are an exercise that is more enjoyable once you've built up upper body some strength.
Traps / delts
Shrugh
Lateral raise - these are HARD. 10 lbs might be too much right now. The key is to do them slow and not to swing the weight.
Seated rear lateral raise - again, hard and less weight - these are pretty small muscles.
Front raise - these can be done as discribed or with palms facing for a different kind of burn.
I'd pick one or two from each group (chest, back, tris, bis, shoulders) and do them as your workout.
For your legs, it does pay to work them - they are big muscle groups and they burn a lot of calories repairing themselves. If the squats hurt be sure you're doing them correctly first, and if it's still a problem try
sissy squats instead (you don' tneed weights).
Lunges are another that are tough- perfect form is essential. A wider stance often helps with balance - and getting it perfect is easier w/o the weights - believe me, you'll still feel it.
HTH
Nat