How often should you go to the gym to get your muscles bigger?

Depends, if you have alot of body fat it will take longer to see the results because they will be hidden under the fat. If you are lifting heavy weights and do less reps, i belive it builds muscle and body mass quicker than doing less weight and more reps. simply because you are putting stress on the muscles and the muscles grow bigger to be able to cope with the stress. However it's advised you change your workout every 2 months, because when your muscles had fully adapted to the stress they will stop growing. 1-2 Months of heavy weight lifting and you should be able to see some nice results.