when bulking up, ive found that diet is definitely very important- as important as workin out.
im currently in the process of bulking myself, and i base most of my diet around complex carbs and protein...
most of my carbs come from brown rice, oats and multigrain bread, with my protein from shakes (HP 100 and dymatize 12hr release), chicken, tuna and eggs.
ive only just got into dieting in the last 6 months, but the gains have been awesome.
stick in there