Going to take my first crack at one of these on Saturday.  I have a 6-1/2 pounder and will be using a WSM with charcoal and hickory.
How far in advance should I season the meat and any other pointers are humbly welcome.
Thank you.

FWIW I let mine warm to close to room temp. Slather it in mustard, then cover with paprika, pepper, chilli powder and usually a brown sugar seasoning. If I am doing a big one I'll pre cook it in the oven the night before for 7-8 hours at 200 degrees. Put it in the fridge over night then smoke it for an additional 6 hours. I save all the juice and use it to keep the meat moist. Watch how much hickory you use as it can get a bit over powering. I prefer cherry wood.

Everything I've read says that cold meat takes more smoke.  I put mine on right out of the refrigerator.   I usually apply a dry rub on 24 hours in advance, but I doubt that it needs that much.

http://amazingribs.com/tips_and_technique/zen_of_wood.html

Is there some kind of a formula for weight of brisket/time smoked? I smoked a 3lb brisket in a WSM with charcoal and hickory and it was kinda dry, smoked it for about 5 hours at 225

Every piece of meat is different.  It depends a lot on so many factors but particularly the grade of meat.   The rule of thumb is about 1 1/2 hours per pound at that temperature, but that is just a basic guideline.   You really have to cook to internal temperature and there can be a lot variability.

What grade of meat did you start with?  Did you wrap in foil after a few hours for the "Texas Crutch"?   Did you keep a pan of water in the smoker?

Spent the better part of last night perusing that site.  Talk about being schooled,  damn.  Thank you.