yes very simple EAT!
i managed to put on 10lb in my first 2 weeks of MT classes. Mind you not all was muscle, so i backed off of eating a bit.
a little tip, the best anabolic i have found that puts on mass and very little fat is milk 2%
1% sucks and 3.25% and chocolate just bite for lean mass.
next best for me would be a mixture of lean beef and rice, cheap and put mass on like a motherfucker. don't forget to droun the fucker in soya souce