First of all, get experience and knowledge in many different systems (e.g.: MS, Unix, Linux, Cisco, Mac, etc.) and learn how to make them work together. Use your house LAN and your free time now to interconnect them in ways that would be useful to potential LOCAL clients. Combining free Linux applications (installed on cast-off computers your customer has in a closet) with local licensed applications can often save a small LOCAL company a lot of money.
Secondly, make a business... I suggest an LLC or an S-Corp... with business cards, letterhead, and web site of your own (I now use Bluehost).
Thirdly, get out there and join local business associations, clubs, and even fraternal organizations (Elks, etc.) and hand out business cards. This is the old-fashioned form of networking.
I subsidize my retirement income with remote administration of several databases, VPN networks and backup systems. Plus I have one Internet web forum that uses advertising to give me a small income.
You won't get rich but since you have to be around the house anyway you'll get some income (possibly), some more experience (probably) and have some interesting stories for when *you* retire. :)