Diet and Nutrition  the most important part bodybuilding. You have to eat good to look good and if you want extra then eat great. You need protein, and you don’t need fat. Stay away from JUNK foods. Cookies,pizzas, chips, candy, chocolate, cake, fast food, fried food etc.  There is a healthy fat. This fat can be found in meat, nuts,fish and some oils such as flax seed oil.
People looking to build muscles often face problem of gaining weigt  and reducing weight, believe me, gaining weight is equally or even more difficult than loosing weight.