jKiska has the usual JavaDoc API documentation. Looking at the menu on the left side, you will see the menu item “JavaDoc”. Clicking on it will bring you directly to the API doc of the current stable release.
There is also a user guide available. This document is still in progress. Documenation for some packages has been written, but not for all of them. Clicking on the item “user guide” in the menu on the left side will bring you directly to it.