Go to
www.bodybuilding.com or
www.gymaddiction.com for great lists of exercises and useful articles about weight training. Make sure your diet is good, and maybe even consider protein bars or shakes to increase protein intake which helps muscle during recovery. Don't have too much though, there is a test on the first site above telling how much to take based on bodyweight. Above all this though,,, go into each workout ready to push it as hard as you can, doing sets of between 8 and 12 reps on each exercise, and make sure you rest and recover in between gym days.