I'm looking for some more detailed documentation for Sonar VS.  I can find some books related to Sonar 7 and 8.  Is either of these versions comparable to the VS version I have on my V-Studio 100?

Sonar VS (the version that comes with the VS-100) is closest to Sonar 8.5.
 
Don't let the toolbar fool you. It looks a little more like the X1 toolbar, but it isn't. VS is a stripped down version of 8.5, or maybe even 8.

I bought a VS-100 recently. Sonar VS, which came with it, was good enough to confirm that I liked the Roland, which comes at a good price.
However, I quickly found that Sonar VS was not capable of doing what I wanted done with it, and I upgraded to X3 producer within days. Should you decide to upgrade to any other Sonar product, remember to register your Sonar VS and benifit from the "registered customer" discount you get.

Regarding books on Sonar, I'm learning a lot from "Making Music with Sonar Home Studio" by Craig Anderson. ACT, Boost 11, Dimension Le, are programs that are either in VS 100 or on the included Sonar 7xl cd. I will be using Sonar 7 with my VS 100. They appear to work seamlessly together.