I treat 9-9 as I would 5-5 and up, for the most part. If I hit a set with them, I usually win a decent pot, if I don't, I lose. I'm pretty new, and still working on various way to play different hands, but I don't like to raise these types of pocket pairs in EP. Mainly, due to the 7:1 ratio of flopping the set. It's very hard for me to call any type of bet with overcards on the board, when I miss a flop such as this. If I was a better, more experienced player (especially after the flop) I'd probably raise more. I think I get better overall results just limping, not only because I'm saving a raise 6 of 7 times, but also because when I do hit the set, many players with TP will put me on some type of draw, because I didn't raise, and oftentimes that leads to them betting in order to push me out. Remember, I suck, so don't listen to me.