Greetings young brother,
You have kindly been given a lot of information from these guys on training and nutrition, and you should DEFINATELY listen to it!
Take it from me bro, when they say eating is the most important. I have tried every supplement under the sun, and all I got from it was less money, more bills! I wondered why I didn't gain any muscle when I was taking cell tech, protein powders and NO-xplode. It's because my diet and training weren't in check.
You must read and research, read and train, research and train, and all over again!
I went from 129lbs to 160lbs in a little over a year. I did this by eating as much as I could (healthy foods like tuna, chicken, eggs, pasta) and training heavy. I also trained with COMPOUND EXERCISES These are exercises like Bench press, pullups, squats, military press, exercises that use more than 1 muscle group to do the work, that activate MORE MUSCLE in your body.
Drink lots of water. Eat smaller meals more frequently.
5 small meals every 3 hours is BETTER than 1 or 2 big meals everyday.
For supplements, if you MUST buy something to help, the only one I recommend to you is Muscle Milk. It will give you protein, calories, healthy fat and carbohydrates. It worked well for me and others. Other than this product, spend your money on vitamins and whole foods. THEYRE THE ONLY THING THAT WILL PUT ON MUSCLE!