I think Kollision will weigh in here sometime and give an input as well.
What I think is that you should build up a base first of all. This could take weeks. Building up a base should consist of doing a higher rep range to get your muscles accustomed to the movements and the stress of the weights.
So I would focus on doing 3-5 sets per exercise and use 10-15 reps or 8-12 for exercises you feel more comfortable with.
I'd say give it 6 weeks of training like this. It can still be intense, in fact even now, I prefer to be around the 12-rep range because the pump feels so good, a feeling you can't get by just doing 3-6 power reps. I like to really feel the sqeeze and blood flowing through the muscles.
I think if you went heavy right away it would be too much stress on the muscles. By doing the higher reps you can still increase weights. Just add a bit of weight and pump out another 12 reps and if you keep adding weight and can only get about 7 or something, maybe the next week at that same weight you'll get up around 10-12.
So you can still get bigger and stronger by doing higher reps and it will be better for you just starting out. Just don't do what I see some people do in the gym, doing high reps but not even pushing it at all, no struggle, no fight, just movement. It can be and should be very intense.
When I say 3-5 sets, I usually refer to 1-2 warm-up sets with lighter weights to get the movement down and then 3 working sets.
Ok, I better get back to work now, don't want to get into trouble for using the internet at work