its simple.
1 - lift weights in the 6-8 rep range - at least 3 sets each bodypart twice a week - the perfect range is 42-66 reps each bodypart twice a week for maximum mass as per studies.
2 - focus on compound movements for each bodypart i.e. bb/db bench, squat, deadlift, bb/db rows, bb/db military press, barbell curls, skull crushers, etc try
3 - try to increase the weight or number of reps on each exercise every single workout.
4 - drink milk before and after your workout
5 - increase calories, by 500-1000 calories a day.
6 - try to get your diet close to a 40/40/20 ratio of protein/carbs/fats or maybe 40/30/30 p/c/f
7 - eat every 4-5 hours, breakfast/lunch/dinner/before bed - no need for the every 3 hours, its a myth.
8 - weight yourself before you start, measure your bodyparts too, and every month do the same again, if you are not increasing, then lncrease your calories.
9 - do not waste money on bulshit supplements. The only ones you should use are whey or casein, creatine, and multi vitamins & minerals, with extra vit c
Good luck.
if you have any questions ask away.