First of all you'll need to download and install the MintCoin Wallet in order to start Minting
Download the bootstrap and MintCoin.conf and add it into your installation directory
You can buy mint at the following exchanges. After you have bought it you need to send it to your wallet.
Just hold on to your MINT in your wallet and after 20 days you will get your first Minting Rewards.
How To Mint