I'm a
travel agent, but I work in an agency. Here's what I know about it.
You can be a travel agent at home. You need to sign up with a host agency, this allows you to use their IATA number to book with the various travel companies and airlines. They'll give you access to their booking engines and a certain amount of support. How much support will depend on what host agency you use and what agreement you make with them, and the level of support will determine how much of your commision you split with them. The more support, the less commision you keep. As you get more experiance and need less help, you should be able to change your agreement to reflect that and keep more of your earnings.
In all setups I've seen, you are considered self-employeed, meaning you pay both sides of Social Security and you have to pay your own taxes (they don't withhold them for you). You may also need to get your own Errors and Omisions insurance (it's like malpractice insurance for travel agents)as your host agency may not cover you under their own policy.
You also need your own equipment, a good computer, broadband internet access, a dedicated phone line for buisness, and a fax machine.
And remember, you work on commision, so you don't get paid until AFTER your clients come home from a trip. Unless you get lucky and your first few clients are last minute bookers, you may not see your first commision checks for 3 to 6 months. You also work for free a lot, as people you make quotes to don't always actualy book anything.
You should have a lot of knowledge about a lot of aspects of the travel industry, not just Disney. You may want to limit yourself to being a Disney specialist, but, especially in the begining, that is also going to severly limit your client base. Many, many people book WDW trips on their own without the help of an agent. Heck just look at these boards! This means you need to know all about cruise lines, including all the places they cruise to and how cruise bookings work. You also need to know about the most popular vacation spots like Las Vegas, New York, London, Paris, Italy, Greece, Austrailia/New Zealand, and any place else you frequently hear people say "they dream of going to one day". You have to be the expert, that's why they are comming to you and shouldn't have to look up basic information in a Frommer's guide book when they ask you questions.
If you're interested in being a travel agent for free and discounted travel for yourself, you may be disapointed. First, you have to be a full time travel agent to get those discounts (your host agency has to send proof to IATAN or CLIA so you can get your i.d. card). Second, the discounts ain't so great these days, and "free" pretty much doesn't exist. And the discounts may only apply to YOU, and not your family traveling with you.
I'm not trying to discourage anyone, it's a great job and being able to work from home has benifits all it's own. But if you dream of making high five figures every year and traveling for free everywhere you go, well, you've picked the wrong industry!