Oops. My bad.
There are two ways to approach this. One is to soak the beans overnight. Pintos swell about twice their size, so this is a safe approach.
Or, if you want to start cooking immediately, you want the water level at least twice the depth of the beans. Check them after a few hours to see if you need to add more water.
I included a picture of my maiden voyage of the WSM. It includes beans and cornbread. The ribs were some of the very best I've ever eaten. We're saving the briskett and butt for later.
My cheapie digital doesn't do so well indoors. The side includes home made cole slaw via wifey (excellent) and a slice of raw onion. It was all very tastee!