First hand advice (Score 5, Interesting)

I am a self-taught geek, similar to you. I was a construction worker, and I wanted to change careers. I don't have a college degree. I built my skills by taking a few night classes at a local community college and by spending a couple of hours a night (or more), every night, working in my home lab, doing networking/IT kinds of things, and writing code. Next, I got a job doing some IT work for a construction company, on a project where a lot of construction knowledge was needed.

After I got to the point where I felt comfortable with my skills, I put together a resume and got an interview with a small IT consulting company. I offered the company the following deal: Pay me whatever you want for 90 days. If at the end of that time I have demonstrated sufficient ability I want a raise to market rates. If not, I will move on, no hard feelings. Within 45 days, I got the raise. Within 3-4 years, I was making 100k a year.