Lets see, if you got the face frame clamp, use it when screwing the boards together. If you didn't get it, you can get buy with an F clamp, but the face frame clamp is a lot faster.
Personally, I try to put pocket holes where the are unobtrusive. On the outside of cabinets when they are going to but against a wall or something, and on the inside otherwise. Sometimes, it is wise to clamp the face frame assembly down before beginning to drive your screws to keep the frame from shifting DAMHIKT.
Normally, I use the 1 1/4 screws for 3/4 material. The screws come in both coarse and fine. I can't remember which is for what, and I have both, but most times I just use the fine ones.
Make some test joints in some scrap at right angle joints to be sure you don't have your bit depth too deep. If it is too deep you can sometimes have the point of the screw come through, again, DAMHIKT. :roll:
Lastly, if you break your step drill bit, only buy the Kreg brand. I dropped the drill and broke my original one, ordered three from WW supply (not Kreg) and all 3 broke the same day. I have since bought 2 Kreg bits and still have them both.
Other than that, a little glue as Dave suggests, and you will be cooking with gas.