Well, you didn't really provide much information to work with, so it's hard to say. I would recommend building a workout plan around compound movements using free weights. There are lots of good exercises that will hit a lot of different muscle groups, but it really depends on what your goal is. Some of the best overall exercises are:
best5everything.com/best5ListPages/exercisesbuildingmusclemass62006.php
Most importantly, eat a ton. If you don't eat, you won't grow.