How to build muscles on my arms?!

How to build muscles on my arms?

Well I am born this way: my arms are smaller than my body, now that I have been going to the gym for almost 3 weeks now but my arms are still small it is toned yes but it lacks mass any suggestions?

follow these 2 things...
first of all, u need to eat! protein and lots of it, diet is 50% of weight lifting... and this is where most people fail... eat a bunch of protein immediately after u lift!!!

the second thing is, do heavy, basic lifts.. heavy barbell curls, dips, triceps pull-downs, and hammer curls..

build the tricep... the tricep makes up 66% of your arm..

there is a muscle under the bicep called the "brachia" exercising this muscle will build the bicep ..."bulge"
do reverse grip curls, and hammer curls for this.. hammer curl is a curl with a dumbell, lifting it as u would pound a hammer..

wait 2--3 days between arm work outs.. the arm muslces are small, and are exercised whenever u do any workout of the upper body... so, if u are doing your whole body, blast the arms only once a week!! and blast them by doing 4--6 sets of heavy stuff... and then go eat!!!