Wiring requirements for garage and bedroom addition

Question

I've just added a new garage and bedroom and am about to wire them. I've done a lot of wiring in my house, know all the basic requirements for how wiring is run, etc, never had a problem with inspection. But I've never done a garage or bedroom. I also haven't carefully explored which circuit I can easily splice into yet. I want to check the following assumptions.

Garage: going to splice into a circuit that has some outlets elsewhere. I will wire for 20A but use 15A outlets.

1. One circuit in garage for outlets, wired for 20A, GFCI'ed, shared with other power in some other rooms at my discretion. I will make sure I'm not worried about so much shared that I will blow the circuit using power tools in the garage.
2. Garage lighting to be run at 15A, most likely shared with some other lighting circuits in the house.
3. Bedroom: Is it the case that I need an AFCI circuit breaker for any circuit (including lights and outlets) in the bedroom?
4. Is is allowed to shared the circuits in the bedroom with the garage? Is it a bad idea to have the garage AFCI'ed and GFCI'ed?

Answer 1

As recommended by wallyk and yurly, add another circuit or two. There is usually no way to tell exactly how may outlet and switches etc., are on the same circuit. If there is no spare breakers in the breaker panel, use tandem breakers. This will allow two circuits to reside in the same space as one.

There are tandem breakers available by all manufacturers, I believe.