Steem is solo mined only, there are no pools and the design is such that it makes it pointless to have a pool for mining.

If you are looking on how to sart mining you can check my guide here, should get you up and running: https://steemit.com/steemit/@cryptos/getting-started-mining-steem-on-windows

You should however wait two more days before starting as there is a hardfork coming in roughly 48 hours that will implement some changes regarding mining (fix an issue).