S.B.
Here's what I can tell you: You absolutely must find a current MT that needs help and is willing to take on an apprentice. My sister is an MT from home and it took her a full 2 years to even get to the point where she felt comfortable doing it on her own. And there are so many out there these days, that competition is fierce and it is extremely difficult to get work if you're brand new. So - find some in your area and talk to them about working with them.
A word of caution - this is not a lucrative job at all. And it absolutely is not something that can be done with little kids underfoot. My sister has two kids, and really thought this was the perfect way to "stay home" and also earn money. Now she stays up till 2 or 3 in the morning to get the work done because since you are transcribing tapes, you simply can't effectively do that with kids running around and all that background noise. She enjoys it, though, and finds it interesting, but she doesn't come close to making a "good" salary, nor is this something that she can easily do w/kids like she thought.
My sister works I think about 15-20 hours a week, and made about 5K last year (you're paid by the word or by the page). The woman she works for is considered a successful MT, has grown children, works about 40-50 hours a week at home, and makes about 40K. So just food for thought there.
Good luck! S.