@LK_Ceelos You mean you're trying to put on muscle (lean body mass) not "weight". If you want to put on weight just go to McDonald's, Burger King, Pizza Hut for 6 meals/day and remain very inactive and I promise you'll gain weight quick.
For LBM there are no huge secrets other than consistency when covering all the mandatory requirements such as actually working out properly and consuming a healthy balanced diet. The problem is 90% of people who don't even know where to begin don't put enough focus on learning the basics, so that is what I suggest. Expand your knowledge about training & dieting so that the question you have are much more specific and related to those main required areas.
For my clients, even if you want to just be told what to do each day by a trainer I still insist on educating them as we go along each time we speak. You have to have your own understanding of everything to really make an significant long term changes with your body/physique. Plus I rather not repeat the same basic info, and unless clients have a base of the basics we cannot even begin to discuss or assign the more advanced dynamics of dieting/training/getting in shape.