AFAIK there is no book on SwitchYard yet, unfortunately. I believe the best resources to learn SwitchYard as of now are the following two official docs:
- Community guides: Home - SwitchYard - Project Documentation Editor
- JBoss Fuse SwitchYard Guide: SwitchYard Development Guide
After getting ideas of what SwitchYard can do with these guides, then play with SwitchYard quickstarts: switchyard/quickstarts at master · jboss-switchyard/switchyard · GitHub
I'm sure this is the shortest path to master SwitchYard.
Hope this helps,