If it's not locked you don't have to unlock it. It will mint automatically.
And when will minting start/how will I know how many coins I have Minted?
Not sure when minting will start. I think it is supposed to start after block 5000, or maybe not until after all POW is done.
You will see staked coins in the line in the wallet that says stake. They will be held there (not available for transactions) until the stake is confirmed 520 blocks. Then they will go back to your available balance. You should see minted coins as a transaction the the ledger.
Max height: 10000 (after this network will not accept PoW)
True, but the POS should start after block 5000.
static const int MODIFIER_INTERVAL_SWITCH = 5000;
if (IsProofOfStake() && nHeight < MODIFIER_INTERVAL_SWITCH)
return DoS(100, error("AcceptBlock() : reject proof-of-stake at height %d", nHeight));
this is preventing any stake before block 5000. After that you just have to get lucky.