I used to do barbell (preacher) curls, cause i could see my muscles wanting to rip through the skin in the mirror. Now I do standing dumbell curls. Just what I like. I never found one to be better than the other. But I would follow jp and abear's advice, they're old and experienced,lol. J/p yall.
I think it's better for beginners to start on basic excercises (ie. push ups, chin ups, dips, etc) and work their way into free weights.