Muscle Milk is great but taking weight gainer will also help you gain weight. One dosage of weight gainer is as many calories as you would eat in a full day. If you go to GNC, they'll give you all the advice that you would need as well.

When working out...just remember Chest & Tri, Back & Bi, and Shoulders & Legs. One day focus on chest and tri's then the next day do back and bi then shoulder and legs on the next day. It just all works out together and throw in abs on any of those days.