You should try machines for 2-weeks to 1 month for 15 to 20 reps.
Try some free weight as well. Focus on technique. The first month is more about getting your body ready for more serious weight training.
Arnold S recommends in his Encyclopedia that beginners concentrate on Bench Press, Dead lifts and squatts to build mass.
Try buying some magazines and focus on beginner routines mentioned in them.
Try finding experienced people in the gym to ask for pointers, check on your form and assist with spotting.