CMake documentation is available as follows:

• Mastering CMake - the 385-page book by Ken Martin and Bill Hoffman,
  ISBN 1-930934-16-5, published by Kitware, Inc.
  Installing CMake
  Running CMake
  A quick introduction to CMake syntax
  A simple example
  CMake Wiki Page
  CMake FAQ Page
  

For additional information, refer to the CMake mailing list, or study an existing implementation (such as ITK or VTK or VXL).

Documentation for CMake 2.4
Documentation for CMake 2.6
Documentation for ctest 2.6
Documentation for cpack 2.6