Picnics or Butts go about the same. Here is some info but at 225*F many of use have found that they go closer to 2 hrs/LB. I am including my Rub and Finishing Sauce Recipes...JJ
http://www.smokingmeatforums.com/t/57139/basic-pulled-pork-smoke
Try this... It is Mild and compliments different style sauces well...If you want spicier increase Blk Pepper to 1T and add 1T Wht Pepper and 1T Mustard powder.
Mild Bubba Q Rub
1/2C Sugar in the Raw (Turbinado)
2T Sweet Paprika (Hungarian)
1T Kosher Salt
1T Chili Powder (contains some Cumin and Oregano) Ancho Chile is same without cumin, oregano etc.
1T Granulated Garlic
1T Granulated Onion
1tsp Black Pepper, more if you like
1/2tsp Grnd Allspice
Cayenne or Chipotle Pwd to taste, start with 1/2tsp and go from there.
JJ's Finishing Sauce
2C Apple Cider Vinegar
2T Worcestershire Sauce or more to taste
1/4C Brown Sugar
1T Smoked Paprika
2 tsp Granulated Garlic
2 tsp Granulated Onion
2 tsp Fine Grind Black Pepper
1 tsp Celery Salt
1 tsp Cayenne Pepper or Chipotle powder. Add more if you like Heat.
1/2 tsp Grnd Allspice
Combine all and whisk well. Let rest, at room temp, 30 minutes for the flavors to meld together.
Mix into the Pulled Pork to moisten and flavor the meat.