I've been trying to bulk as well and I found some good info online. you should try to look for a TDEE calculator (or use the one I used http://www.fitnessfrog.com/calculators/tdee-calculator.html ) and then eat 250 calories over your maintenance calories if you're a man and I think around 150-200 for a woman, but don't quote me on the woman part. From what I read, eating those extra 150-250 calories will minimize the fat that you gain.