There is how to paint (xxx main), how to tune nitro engines (rcca) etc. etc. dvds out there but when is someone going to come out with a How To Tune DVD which will have suspension and diffs/driveline on?
Not a dvd, but the xray buggy manual has an extensive section on what each suspension adjustment is for and what it does in each direction of adjustment. When I was running my LP buggy, it was a great reference in getting it setup. You can find it on xray's site and download it.