Lessee, I cast on 72 sts, worked 2 rounds of p2, k1 (rounds 1 & 2) then knitted 2 rounds (rounds 3 & 4) then did it all again. I used a multiple of 3 and didn't add in the +1 because there is no edge to need an edge stitch. When you knit in the round you always are knitting from the RS so for stockinette you just knit away. The purl rows in this pattern turn into knit rows. It's easy once you know how. Until you've knitted in the round, this probably makes absolutely no sense whatsoever, don't worry, when you get there it will.