Hi James,
I've done software development work and other computer-related jobs on the side, but I've always had my "day job" to fall back on. Thus I never crossed the line to making a committment to survive on my own ability to generate clients.
I've read plenty about it, and talked with people about it, but ultimately I guess I'm chicken. (Darn, no smiley with a chicken in it!)
I wish you the best in whatever you decide to do.