When I first got out of high school, I went and did a 9 month IT course at a crappy unacredited technical school (not saying that technical schools are instrinically crappy, it was just that this one was). My family didn't know anything about post-secondary education, so I thought that a certificate would carry about as much weight as an actual degree. Well, I think that's one of those life mistakes that one makes, and when you have children, you try to watch out for them so they don't make that same mistake. I did eventually end up in a tech job. It was high stress, and I found that I really didn't care for it. I was eventually laid off, because the company really wasn't making enough money to pay me. I made the decision that if I were going to go any further with my career, I'd have to get a real education. I really wasn't that into IT, so now I'm in college for something completely different. I'm still glad I can do IT stuff, because I actually work for my university now, doing what I'd call "light" IT work (i.e. fixing broken down computers, swapping out hardware, etc.).
A lot of what people have already said rings true. Experience carries a lot of weight in the IT business. On the other hand, if you're going to work for a large and reputable company, a degree, along with your experience, is going to help open doors. Even if you don't get a position straight out of school, be sure to keep on top of the business until you get a job. Chances are that technology will change six months after you're out of school. I also echo the sentiments that you should pursue a BS. Now if you are going into programming, you can demand a very high starting wage straight out of school. If I were to go back to school for computers, I'd probably get a BS in computer science, which entails a lot of programming, and then teach myself IT on the side. Of course, programming requires a lot of math, more math than a lot of people realize. If you're good at math, programming may be right up your alley.