hypnosec writes "The open-source Radeon Gallium3D OpenCL stack has been modified to support Bitcoin mining through the use of mining application 'bfgminer.' To mine Bitcoins using the open source GPU driver, one must use Tom Stellard's non-stock branches of Mesa, LLVM and libclc OpenCL library. Further, bfgminer must be patched as well. Once the patches are applied and modified code of the stack is used, users will be able to mine Bitcoins using the Radeon HD 5000 and Radeon HD 6000 graphics cards; however the cards have to be pre-HD6900 Cayman in case of the HD 6000 series."
The best book on programming for the layman is "Alice in Wonderland";
but that's because it's the best book on anything for the layman.