Most would recomend using 1 only for your first....so you know what sides you get from it . If you ran 3 and got a bad side....you wouldnt know wich compound it was from .
People run more than 1 for more/better results of course . say you run a test deca cycle....it takes me 5-6 weeks to get the effects....throw some dbol or a-bombs in wk 1-4 to kickstart you for instant effects .
heres a site i like > http://www.steroid.com/drugprof.php