For starters, there is a page on caching in the official Cocoon docs: http://cocoon.apache.org/2.1/userdocs/concepts/caching.html
One piece of information which seems to be missing from that doc is that SourceValidity is from the Apache Exalibur Source Resolving project with packages org.apache.excalibur.source and its subpackages.
JX templates will be cacheable in Cocoon 2.2. There is information about caching JXTemplates in the "Advanced" section of JXTemplateGenerator.
There is information about caching XSP pages at XSPCachingWithCocoonHEAD.
- I'd really like to see some information on how to debug caching problems. For instance, if I have a complicated pipeline, is there any way, by looking in the logs, to see which component gave me cached output instead of fresh?