There are three main ways to go with multitrack recording for us amateurs: 1) four-track cassettes, 2) four or eight-track minidisc, 3) hard-disk recording, either as a stand-alone unit or PC-based. I had a four-track cassette unit for many years, then upgraded to a four-track minidisc about four years ago. The cassette units are inexpensive (less than $300), but the difference in the sound quality and editing capabilities are a quantum leap better for the minidisc. You can get a Yamaha four-track minidisc new for about $500 now, or you can get used Yamaha or Sony four-track minidiscs on eBay for much less. Yamaha also makes an eight-track minidisc; I wish I had those extra four tracks. The stand-alone hard disk multitrack recorders are nice, usually with built-in effects such as reverb, chorus, etc. You'd need a way to archive your data, such as a Zip drive. A newer model is the Roland BR-8, an eight-track deck that records directly to 100 mB Zip discs. It has the Zip drive built in. It costs about $695. I've used that one extensively, and it has a lot of nice features. The PC based units take quite a bit more technology than first meets the eye. The software is quite expensive, and you need a high-quality soundcard, as well as a relatively high-end processor and a big hard drive for storage. I'd say your best bet is getting on eBay and picking up a used minidisc or checking out the Roland BR-8. Good luck!
Terry, home-recording fiddle player