Hi everybody.
I'm a teenager, and I've always had a nice set of abs, but very lanky arms.
I Work out 5 days every week, but i think i need better arm exercises, because I'm clueless.
Also, could it be just because of the fact that I'm probably white muscle tissued, and its the red muscle tissue that gives you a nice bulge?
Thanks,
David

Your shoulder has 3 movement, front, side and back, Do exercises to put pressure against these muscles, for example push ups for front shoulder (and biceps)... and "backwards pushup" for the back shoulder (and triceps), but when you do it backwards.. go down a little bit, this has more risk for injury. And in general holding weights out in front, back and sides will get the entire shoulder.

"Elbow" has 2 movements, flexing (bicep) and extending (triceps). There's also "twisting" of the arm, which should be light weights like the wrists so you don't pull the delicate muscles and they're easier to pull, start at 3lbs, then 5lbs, 8lbs, and maybe 10lbs, but talk to a trainer if you want to do 8 or 10...