Plan what you want to end up with before you start. There are some basics in what you want in a rig, are you going to drive it on a daily basis, is it going to do trails only, are you going to tow it on a trailer, flat-tow or drive it to the trail. Take into consideration as to weather you are going to bash the crap out of it or do you want to keep it nice looking. Don't under-estimate what you want to end up with. It sucks to buy 35's and then decide you would have been better off with 37's or 33's.
First I would decide what size tires you want since this is what everything else revolves around.
Next how much lift is needed to fit those tires.
Now determine the gearing for the tires.
Once you figure out these things you have your basis of what you want. The next thing to figure out is the options you want that can be done while you do these to you truck like lockers, highsteer, etc. etc. that can be done as you build to eliminate having to do it again.
You don't have to go crazy wild to achieve a very competent rig, currently I have 33's, about 4 1/2 lift, limited-slips and stock gearing, but don't tell anyone they won't believe I go where I do with such little of a build.
Now the rest of the stuff is gravy, like installing crawler gears and such since you didn't need to take them into consideration to build it initially.
