To start mining go to Help/Debug/Console

setgenerate true

The source will be available on github shortly. Its not exciting, just bitcoin really. The interesting part will come when the Proof-of-Intent is introduced, but this can only be done once sufficient transactions are generated. POI is superimposed on POW. A search is made not just for the hash but also prior occurrences of the public address in the blockchain. This validates the transaction.