First of all if you want to become a guide you must think of it as a business. That being said you'll need money for a start-up. Truck, boat(fully stocked), Trailer, Rods, Reels and flies. Next you'll need insurance, truck, boat, trailer,health for yourself ($5000 per year) and at least a Million of liability insurance(about$1000 per year). Next you need an advertising budget to attract customers, you can also use a flyshop as a booking agent and pay them a fee. Make sure you have all your permits and licences. As for guide school, ABSOLUTLY, get all the professional training you can, in casting, boating, and emergency medical. Now your ready to get a lawyer, I would go with a LLC, this will protect your personal assets should something go wrong, you lawyer will advise you on your options. Get a business proposal together listing all expected start-up costs, especially if you need to borrow the monies(SBA is your best choice). Remember that all of your expences are tax deductable, keep good records, and use a good accountant. This just touches the surface, but I hope it helps. Good luck!
The man who coined the phrase "Money can't buy happiness", never bought himself a good fly rod!