Basilisk is a self-descriptive low level library, this is the reason why documentation seems pretty sparse. However the classes are fully documented and the packages are introduced nicely. Anyone that knows how a game may work can begin to code with it in no time, and in a couple of days of training he can easily begin to tamper with the library code itself.
Some examples are provided with the sources, a manual is in progress.
You can access download version of the docs from the sourceforge repository
Basilisk Online Documentation
For a sneak peek you can see the classes hierarchy and documentations online.