Okay, you didn't say what kind of smoker you have and that's the most important part....no worries we can square you away.
Get your unit humming at 250-275F steady.
In the meanwhile, rub your meat with some nice stuff, assuming you already separated the point from the flat. If you didn't that's okay too. You can smoke a full packer easy enough.
Rub it with whatever you like, garlic powder lots of paprika, onion powder, some oregano. Stay away from salt and sugar.....that's important.
Put that hunk of meat onto your smoker and let it be for about 3 or 4 hours. Meanwhile get a squirt gun bottle and fill it with apple juice.
After 4 hrs, open the smoker and squirt that puppy good, then slap that lid back on and forget about it.
Drink beer, rake leaves, sweep the back patio......be productive and stay away from your wife's hair.
After 2 hours, open the lid and temp that puppy as you squirt it more. Yep it is still around 120 or so.....
Close the lid and make sure your fuel maintains the 250-275 heat range.
I cook my briskets at 250-275, but that's just me. You'll hear a lot of howling about otherwise.....but then that's just the flak. If you aren't taking fire, you aren't over the target!
Let that baby smoke on until 155 or so...you'll get that temp. Once you get there....
That's the PLATEAU. Oh hell....that means drink more beer and watch more DVD's.
Eventually (after about an hour or two) the meat temp will stop falling and start rising again. Yes it will fall. Leave it alone. Then when it rises after 2 hours temp it again.. You want at least 180F internal. Keep it in the smoker until it hits at least 170F, then you can foil it and put it on your cold stove to keep warm.
At 165-170F internal you can wrap that baby in foil and leave it be.
Let it cook and you are set. Put that wrapped baby in an oven with the light on for about an hour and you are set for some nice meat.
Then you are set. Soft, easy pulling meat that friends and neighbours will love.