You can unlock the account using below command on geth console:
If you have not created more than one account on geth then use -
personal.unlockAccount(eth.coinbase, 'your account password in quotes', 0)
The first argument in above command is the account hash(address), second is the password in quotes and third is the time in seconds till the time you want the account to be unlocked.
eth.coinbase is default account which gets created while initializing genesis block. You can also use eth.accounts in place of eth.coinbase
If the account you are trying to unlock is not the first one then use the index of your account from this array - eth.accounts.
For instance, if my account is at second index then you can use it like this -
personal.unlockAccount(eth.accounts, 'your account password in quotes', 0)
Hope this helps.