Donnie, We discussed this by email, but to elaborate a little . . .
You are set up when you play live where the keyboard and vocals are already nicely mixed on your mixer. I like to make the recordings in stereo, and you are already hooked up to do this, since the KN5000 has left and right outputs that are already panned for stereo.
Your mixer has either tape-outs or line-outs. Just hook your mini disc recorder up to these outputs and record.
After you get some songs that sound good, then you can dub them to cassette, or transfer them to your computer and make CD's, MP3's etc.
What you can do in the computer depends on the software you have, but almost all the newer computers have capabilites that weren't available in the best recording studios just a few years ago.
I'm certain there are others here that know a lot more about this than I do, but one of the great things about doing a single is that you have total control over what you're doing and it's easy to control all the parameters like e.q., balance, overall sound level, etc. You don't have to worry about miking the drums, or the sax player hitting a bad note or the bass player running off with the guitar player's wife.