I want to build a simple wind generator?

The other respondent didn't answer your specific question (your Additional Details), so I'll take a crack at it.

You apparently are satisfied that you have a workable permanent magnet rotor mounted on a shaft rotated by the wind turbine blades. You are apparently only concerned with building the stator through which the rotor will pass.

You can, of course, buy complete, simple alternators practically anywhere, which reduces the energy source of the problem to building the blades, mounting them to the rotor, attaching a tail to the blade shaft for wind to position the blades, and then processing the resulting electrical energy provided by the kinetic energy of the wind-driven rotating blades.

I definitely suggest the above procedure. Here's an example of a guy who did just this

http://www.youtube.com/watch?v=aHB4zxWd3Ls

However ... if you are doing this as a project and do wish to create your own stator, I definitely suggest you wrap the coils around a (gapped) iron core. The increased permeability of that system will provide much greater emf for a given rotation velocity. This will be better all around: the rotor will be overcoming much greater back torque for a given rotational velocity, which will greatly reduce mechanical velocities, stress, and so forth, as well as providing more efficient total energy transfer. An air core stator for a wind turbine would be about as useful as an air core stator for an ordinary motor-generator. That is, pretty much a toy.

Most modern day wind generators use magnets. If you recall basic electrical generation theory, as a wire passes through a magnetic flux it generates current. I won't get into all the equations, you will need an engineering manual on electrical theory to answer that. If you don't utilize magnets though you the only other way of generated electricity is to create a magnetic field using electrical energy. To due that, you must create a stator (an electrical magnet). This electricity can be supplied by the wind generator itself, but it has to exist before it can create electricity. So you must start it off from an outside electrical source, this is called flashing. So it is much easier to just put magnets on the wind generator from the start. The next part, is the design to turn it into a DC Generator. You will need to design it to create a rectified DC wave form. You can't use AC, because you won't be able to control frequency (can't connect it to any household stuff), and you can't store AC. DC has to be supplied to an AC Rectifier that supplies a clean 110 VAC so you can power your house. These aren't cheap, and you have to make sure that you have all the safety devices in place as well (overload protection). Put on that storage devices which can be a whole bunch of Car Batteries and you are golden. I don't want to make this sound daunting. You are probably just doing this to see if you can do it. But just in case you are thinking about hooking this thing up to your house, know what you are getting into before you leap.

Automobile alternators are made to operate at variable speeds. All you need is the wind mill (like a farm wind mill) the alternator a battery and a 12 VDC television. Sorry but that is as simple as I can get.