I didn't read through all the posts, so someone may have suggested these. I have three suggestions: School, Certifications, and Submersion.
First off try to get a degree of some sort, even if it's just a AAS Degree in Computer Science at a local community college. If you have any credits it may not take as long as you'd think.
If school isn't an option or you don't want to spend the time, pick a path and submerge yourself in it. If you want to go the DotNet path then pick-up VS2008 Developer Edition, Sql Server 2008 Developer Edition, and as many books as you can. Yes it will cost some money, but you're talking about a life changing career move so you'll need to invest some cash and time.
Also a huge piece most folks miss when telling someone how to get started are the conceptual aspects of coding. I'd say any good program has more time put into planning the concept then typing code itself. Spend as much time learning the theories behind coding, which generally are language independent. I'd suggest getting Beautiful Code and also reviewing the books at OReilly on this topic -
http://oreilly.com/store/series/theory.html .
Then once you pick a language and start getting familiar with it, start coding! Put together anything, whether it's a program to calculate your budget, your bowling team's scores, anything. Find some practical use for hte code and start hacking. Then when start looking at certifications. Microsoft has several for developers: MCTS, MCPD, MCAD, etc.
So how does this apply to breaking into the IT workforce??? Personally my experience is a degree is best, but many employers will look at certifications second. Either shows you're able to follow through with something. Secondly even if you have no professional experience, I've seen folks carry a portfolio of work to show. If the hiring is done by a CIO or HR department, they probably will look more at certs and degrees, but if the technical side of the department is involved have something to show, even if it's a small sample of printed out code. To a developer they can read this and see how good you are.
With all this said, don't expect to find an awesome job right out of the gate. Try to get a gopher job, which is generally fixing bugs, doing reports, etc... and from here you'll get the work experience you need to really move up in the industry. ALso make contacts!!! Find folks in your area who are coders, whether in a user group, local computer shop, or whatever. Most jobs I've seen folks get around our area are through contacts. The verbiage "It's who you know not what you know" does hold true.
Have fun...
, but my suggestion is to go to school part time at your local community college and try to pick-up an AAS Degree in Computer Science. Depending on the credits you have now it may only be a matter of a few classes, or if you're starting from scratch some technical colleges will give you a certification. But for better or for worse many employers look for a degree of some sort.
Secondly I'd suggest picking a path and submerging yourself in it. For example if DotNet is your route, get