I finally installed the QT Wallet and its fully synced and I've moved my coins from Bittrex to the wallet.

Can anyone explain to me how to begin staking? I've already unlocked my wallet and checked the "For Staking Only" section. However on the Dashboard I see the following:

Spendable: 12000
Stake: 0
Unconfirmed: 0

Can someone tell me what the Stake: 0 means? Am I not staking anything right now?