Checkout qortal.org – there's a wiki with lots of knowledge.

To answer in short, you don't mine. In Qortal, we have a minting process similar to PoS, but you don't need coins at stake, you need a sponsor who sponsors you in order to convert your account into a minting account (which happens 7200 blocks later, so close to five days, I think).

Then, your level 0 account becomes level 1 and your account becomes part of the pool of level 1 and level 2 accounts, which share 5% of the block rewards (5 QORT each block).

The levels are (100% are 5 QORT, each block):

level 1 and 2: 5%
level 3 and 4: 10%
level 5 and 6: 15%
level 7 and 8: 20%
level 9 and 10: 25%

Hope that helps.