I went to guide school a few years ago. I went to Swan Mountain Wilderness Guide school in NW Montana.
It was a really neat experience and I learned a lot, but I would really not spend the money on it. The whole emphasis of my school was horses and packing. It was awesome to learn about all that, and I thouroughly enjoyed it, but it did nothing to teach me how to hunt or guide hunters.
I already had a job with an outfitter prior to taking my guide school (i had already paid for the school before I got my job) I learned pretty much everything from him.
In my experience, talking to outfitters and being willing to start out low on the totem pole, and work hard and you can get a job. You can learn a lot from experienced outfitters and it will give you the knowledge to go out on your own. Send me a pm and I am more than willing to talk to you in much more detail about this. Good luck!