Here's a multi-tracked recording I made earlier this year - my own arrangement of Fats Waller's "Honeysuckle Rose" plaued on acoustic bass, guitar and lead tenor guitar:

Honeysuckle Rose

How I did it:

1. I created a new file called "Honeysuckle Rose" in Garageband on my Mac Book Pro, and set up a basic click track at the preferred tempo.

2. I listened to the click track (quietly) through earbuds and recorded the lead tenor guitar track live using my Zoom H2. (I also recorded the video for this at the same time with my Sony Camcorder).

3. I uploaded the Zoom H2 tenor guitar track as a wav. file to my Mac Book Pro and opened it with Audacity.

4. I used Audacity to check the volume level, topped and tailed it, and saved it as "Tenor guitar.wav."

5 I added "Tenor guitar.wav" to the Garageband file as a second track.

6. I deleted the tenor guitar track from my Zoom.

7. I repeated Steps 2-6 above, but this time played back the Garageband click and tenor guitar and tracks while recording the acoustic bass with the Zoom.

8. I repeated Steps 2-6 above, but this time played back the Garageband click, tenor guitar and bass tracks while recording the rhythm guitar track with the Zoom.

9. So, after three recording passes, I had a Garageband file containing (a) click (b) tenor guitar (c) bass and (d) guitar.

10. I deleted the click track from Garageband, and then synched, panned and EQ'd the three instrumental tracks within Garageband.

11. I saved the mixed Garageband track as "Honeysuckle Rose.wav - and then synched it up with the video in iMovie.

There's a reason for adding the rhythm guitar last - it's to give the feel that the guitar is actually listening to the lead. which it is.

Hope this is of use. It's actually less complex than it might initially look.