If youre looking for info on how to build muscles then one of the best tips you will ever get is to focus your efforts on compound exercises. Compound exercises are those movements which use more than one joint. For example, the bench press is a compound exercise because both the shoulder and elbow joints move. A bicep curl on the other hand, is not a compound exercise since only the elbow joints move.
Compound exercises allow for the use of heavy weights and they stimulate a large amount of muscle. Because of these factors the use of compound exercises in your training program allows for fast and efficient muscle building.
If your goal is to build muscle as fast as possible, then I highly recommend basing your program around compound exercises. Some good ones to start with are squats, deadlifts, chin-ups, and bench presses. With these 4 exercises alone you will have stimulated most of the muscles in the body.
If you feel the need you can throw-in some curls, tricep extensions, calf raises, ab work, etc. But the base of your program should include a heavy emphasis on compound exercises. This is especially true for beginners.
Compound exercises alone are all most people really need, especially early-on in your training career. You can build an impressive pair of arms just by increasing your bench press and chin-up. And, as a bonus, you will also have increased the size of your delts, lats, and pecs. This is the efficiency of compound exercises at work. Improvements in compound exercises will give you more bang for your buck than improvements in isolation exercises.
As always, any training program must be combined with a solid nutrition program to get the best results. If you are unfamiliar with the science behind successful training and nutrition programs then it is always best to consult a professional, especially if you are struggling to put on muscle as quickly as you want.