There is Doxygen content for CBC available online at http://www.coin-or.org/Doxygen/Cbc/index.html. A local version of the Doxygen content can be generated from the CBC distribution. To do so, in the directory COIN/Cbc, enter make doc. The Doxygen content will be created in the directory COIN/Cbc/Doc/html. The same can be done for the COIN core, from the COIN/Coin directory.