The United Sidecar Assocation (USCA) has some free download books on the subject written by Hal Kendal:
The site: http://www.sidecar.com/default.asp
The books: http://www.sidecar.com/links3.asp
A "must read" IMO. The driving dynamics of operating a rig are very different from riding a motorcycle (now there's a big understatement!), but once you get over the shock of no countersteering, and can safely and proficiently handle it, you'll probably find it grows on you - sure has for me... I put on about 12,000 kms total this year on my 2 hacks, my first year of the sidecar experience.