There are countless articles on building bigger more powerful arms here's mine.

I believe best way to build massive biceps is through a multi angle attack. I use three, sometimes four pieces of equipment to properly hit bicep as correctly as I can. I start with dumbells to use in a hammer curl form, a hammer curl is when you keep your hands in same position they would be if they were at your sides, lifitng weight straight up. The hammer curl gives bicep a good stretch and provides additional length of bicep down arm. I then switch to a traditional curling bar which is one of those squiggly looking bars with v's bent into it, from there it's over to old favorite straight barbell curl. If you have one you can also use "tricep bar" which is short bar with oval in center with two handles although I have found this bar to let front deltoids join in too much you might have some success substituting this for hammer curl with dumbells.