First, talk to your doctor to make sure weight training is right for you. Second, hire a personal trainer (at least for a few sessions) to show you exactly how to perform each exercise. The exercises will do you no good if you’re not performing them properly – or become injured.

With that said…
best bicep building exercise is a barbell curl (with varying grip lengths), and close grip chin ups.

best tricep building exercise is close grip bench or dips.

chest – bench press (incline, flat bench, and decline) with a barbell or dumbells.

abs – bicycle crunch. don’t worry so much about ab exercises. with diet and cardio, you’ll see abs no problem. if you have a layer of bodyfat over your abs – you can do ab exercises forever and you won’t see results.

quads – squats. best leg exercise overall. don’t forget your hamstrings…for those – deadlifts.

calves – donkey calf raises and various calf machines in the gym. also – if you can run on sand or use a stairmaster, those will burn your calves.

you didn’t ask about back. to build upper back muscles – wide grip pullups. mid back – bent over barbell rows.

go to a trainer and ask about these exercises and have them show you how to perform them properly.

http://www.amazon.com/New-Encyclopedia-Modern-Bodybuilding-Updated/dp/0684857219/ref=pd_sim_b_title_1

Written by one of the best bodybuilders of all time, this book has exercises for every body part. Many of the sections may not be applicable to you unless you plan on entering a bodybuilding competition, however this is one of the best books I’ve ever read on the subject of bodybuilding. In addition to learning the exercises, you must read the nutrition section. Your diet is about 60% of the whole equation when it comes to building lean muscle mass.

Good luck, be patient, and most of all happy with the way you look.