upper arm flab....

Cardio/Strength training. Working your biceps and triceps. Youtube have tutorial videos of weight training thats focus on these two muscle groups. You are able to watch and learn the correct form.

i was told to take a weight and hold it with both hands behind your head and do presses and that should target that flab under the arm

Well first off, you would have to lose fat, as there is no exercise that is just going to tone up that one part of your body ( unfortunately- wouldnt that be nice haha!) But after you get the fat off, you can do bicep, shoulder, and tricep workouts. My favorite for my triceps are dips and overhead tricep extension. Favorite for biceps are EZ bar curls and cable rope curls, and shoulders are my absolute favorite to train, I like lateral raises and arnold dumbbell presses. Good luck!

http://exercise.about.com/cs/weightlifting/l/blsampletricep.htm

I googled tricep exercises and this was the first link. it shows what exercises to do and how to do them...if you scroll down to about the middle of the page, you'll see a handful of links, one of which is "bicep exercises"

Just fyi

I am working no the same thing. I think that the key must just be to work on your triceps everyday

I really wouldn't recommend that. When you are working out your muscles, you are actually breaking them down, thus they need time to build themselves back up. If you are giving them an intense workout, you aren't going to make much progress with them.