what kind of smoke? black, blue, white?
Black - Rich mixture/incomplete burn/bad spark
Blue - Oil. Rings/valve seals.
White - Coolant. Water getting into the cylinder somehow.
That is just generalized. Some engines have their quirks and do things a little outside the norm. Someone with more experience with the 2.8 will surely chime in and correct me.
When you provide more specifics as to the color, things can be narrowed down more.
As stegomon states. Rebuilds can be anywhere from a day to infinity. Attention to detail, following instructions, using your head, and listening to what people tell you are all key factors. As it is your daily driver and you've never done it before, I wouldn't plan to do it over the weekend without some very experienced help, and even then you'd be pushing it.
It's seemingly always my experience that a job costs twice as much as I plan, plus at least one tank of gas going to the parts store. Then again, I am sometimes disorganized.