Users' guide is a very detailed description of PerfCake for anybody who would like to use it for performance testing, generating load, and or application responses validation.
Following are the links to the documentation of the latest release.
Download Users' Guide 7.5 (PDF) »
Open Users' Guide 7.5 (HTML) »
Looking for a documentation for an older version? You can checkout the
source code repository
on GitHub and build it on your own.