Hi there Matt,
If i understand your question properly, you've managed to skin the figure ok, but you're having problems with moving the arms. (forward).
Theres a couple of things i can think of, which may, (or may not), be some help.
Probly the easiest way is to rotate the shoulder, with the y axis, using the Right mouse button. One thing to watch with that is that you don't go so far as to deform the mesh too badly. (at the shoulder joint).
Another way is to move the 'upper arm' forward, along the X? axis, from the 'arms out' position. (before lowering the arm). Then, you can lower the arm and the upper arm will already be fwd. (or backwards of course).
Its a good idea to have the coloured axis paths showing and experiment, as arms CAN be tricky to get the movements happening as you want them to.
Sometimes you have to think a few steps ahead to get the final position that you want. Good luck. Don't hesitate to ask again if you're still not happy.
I still struggle at times with arm movements, which can be quite frustrating, but can normally be achieved with some experimentation and workarounds.