I've tried gaining weight recently. So far I've gained 20 lbs of muscle in 2 months with fish oil and eggs being the only animal products I've consumed.
My advice to you would be to read
Amazon.ca: Scrawny to Brawny: The Complete Guide to Building Muscle the Normal Way: Michael Mejia, John Berardi: Books There is lot's a great advice in that book on bulking up however most of the their meals are centered around meat. To get around that I cook eggs and egg whites and eat them in place of meat. I've found they also reccommend too much protein. My muscle gains have been fine and I'm eating ~15% protein.
Another recommendation I have is to make a daily nutrition program (it's mentioned in the book) so that you're making sure you're always getting the calories you need (it's very easy to undereat when you're not counting calories). If you want I can post mine.