In most gyms, there are fancy machines. Machines build especially for training specific muscle groups. If you are a beginner, and you never have lived a weight before, these machines can be very good to get you in shape. However, if you have been bodybuilding for at least three months, stay away from the machines. You will get much better results if you use free weights as much as possible. This is because when you are lifting a dumbbell, you are using all those little muscle around the joints to stabilize and balancing the weight.
The most important thing to remember when training with free weights is to make sure your form is right. You should be able to do the exercise slowly and controlled, without bending your back or doing other odd movements. If you can not do this, then you are training with to heavy weights.
It is very important that you focus on doing things right. An injury is the worst that can happen to a bodybuilder. Even small injuries can take as long as three months to heal, and in all that time you can not workout properly.
Arnold Schwarzenegger once said that the one thing that really makes your muscles grow is the last rep. The one you take, even though you feel you can not take another. Push your body out of its comfort zone, but remember to relax and reconstitute. Your muscles does not grow in the gym, they grow while you are relaxing.
If you are serious about creating the body of your dreams, you should get hold of a good workout program with a proper diet plan included.