The first thing you need for the best pulled pork is a "Boston Butt" which is actually a upper pork shoulder.

Here's kind of an interesting fact according to the experts at the National Pork Board of America:
"In pre-revolutionary New England and into the Revolutionary War, some pork cuts (not those highly valued, or "high on the hog," like loin and ham) were packed into casks or barrels (also known as "butts") for storage and shipment. The way the hog shoulder was cut in the Boston area became known in other regions as "Boston Butt."

Your local butcher may or may not display whole pork shoulders in the front of the store. Don't be shy about asking your butcher for a pork shoulder roast, or Boston Butt . I find 6-8 lbs is about the perfect size for this cut of pork.

Brine:
2 Cups Apple cider vinegar
2 Cups water
1 cup kosher salt (it has to be kosher! nothing else will taste the same)
1/2 cup raw sugar
2 tablespoons liquid garlic or 1/4 cup garlic power
2 tablespoons smoked paprika
pinch of white pepper
1/4 cup Pickle Juice
zest + juice from 2 oranges
1LB ice (about 4 cups of cold water) you don't want your brine warm so it cooks the meat when you add it.

Rub:
1 part mild paprika
2 parts light brown sugar
1/2 part hot paprika
1/2 part celery salt
1/2 part garlic salt
1/2 part dry mustard
1/2 part ground black pepper
1/2 part onion powder
1 part salt

Pulled Pork BBQ Sauce:
2 cups cider vinegar
1 1/3 cups water
5/8 cup ketchup
1/4 cup firmly packed brown sugar
5 teaspoons salt
4 teaspoons crushed red pepper flakes
1 teaspoon ground black pepper
1 teaspoon ground white pepper

Brine:
In large pot on the stove combine all ingredients except the ice, orange zest & pickle juice.
Bring to a light boil and mix everything together until everything is well dissolved.
Remove from heat
Add ice and the remainder of the ingredients.
I sometimes make my brine a couple of days in advance and skip the whole stove portion, the dry ingredients will disolve in the refrigerator in a couple of days with a few daily shake/stirs
Put pork in a large zip top bags and pour enough brine to immerse the meat, remove all the air from the bag and leave in refrigerator for at least 6 hours and up to 3 days. this is a taste thing, I like mine brined for 24 hours. If you have any brine left it freezes great or save for 1 hour brine for pork chops sandwiches!

Rub:
Combine all ingredients for the rub I usually just use rubber gloves for both the mixing the rub and rubbing the pork.
Remove the pork from the brine and give it a quick rinse.
Rub all the seasoning into the meat, and re-wrap with plastic wrap and leave on the counter for at least one hour to come up to room temperature.
Don't be shy! It's called a rub for a reason - you have to rub it!

Cooking:
The very best way to cook a Boston Butt is the "Indirect Method" with no flame under the meat.
Medium low heat (225f-275f) for 4-6 hours or until the temperature in the middle of the pork reaches 180f.
Add 1 handful of soaked wood chips to the fire every 30-50 minutes, I prefer fruit woods such as apple and cherry as they are less bitter.

Pulling:
When the meat is done, wrap tightly with foil and leave to cool for about 1 hour, or until it's cool enough to handle without burning your hands. Don't let it get too cool, as it will be easier to pull the hotter it is.
Pulling the pork with 2 forks and rubber gloved hands.

BBQ Sauce:
Combine all ingredients and whisk till all the dry ingredients are dissolved.

Serving:
Place pulled pork in roasting pan on the BBQ with low heat and cover with the BBQ sauce and mix throughly, cover roasting pan with foil and let your guests serve themselves a la carte or on a sandwich.