Welcome to GMSB Ben. I know I haven't welcomed you before when you signed up since I know I'd recognize a swampdonkey when I seen one.
Down to bidness... It's always great to see those who normally aren't familiar to working on vehicles giving it a go. You've certainly come to the right place for help. However, the only help we can give is written in text and maybe a picture or a few. You're not only new to working on front axles, but you mention new to working on vehicles period right? Keeping your safety in mind as well as others, or to keep expenses down in learning the "hard way" in what you'd possibly tear up by making a mistake or not getting it just right, I'd suggest for your first go round with a 4x4 front axle to get with someone who can offer some in person technical support. Even it's some old retired dude that can flip over a 5 gallon bucket and sit, watch and guide you to do it. If it were just a 2wd front brake job including replacing the rotors, repacking your bearings and the whole 9 yards, I'd say go for it. The 4x4 front driven axle is a bit more complex with many several small parts that have to be in specific order and not only that, in the right direction. You'll also have bearing preload to set that is critical so you don't lose a hub which is not likely to literally lose it, since you have other parts that'll keep that from happening, but there are things you can tear up that become expensive and worse get some high speed wheel wobble, no telling what might happen. There's also a couple tools you need that are more than just common tools, like spindle nut socket, the correct size pickle fork for removing the ball joints so you don't damage the knuckle. Ball joint press tool which can be rented/loaned from most auto parts stores. I know it sure seems I'm trying to discourage you from tackling this project, but I'm not. I'm just suggesting if you have a buddy, neighbor, family member or someone that is semi mechanical and is familiar with working on vehicles, even if they haven't done this task, they'll at least recognize some similarities to other things they've worked on, and they'll also understand the importance of being critical of the order and the direction that parts go back together. So if you can get some help this time, I'd wait til they could make themself available for you, and you buy the beer.
Sounds to me you're just wanting to go through the axle and make it like new again when you use the term rebuild. If that's the case, rather than "check" the u-joints in the axle shafts, I'd just plan on replacing them unless you know for a fact they've been replaced recently as in the last year or so. You'll be that far into it anyway, and if you have the $40 or less to spare for the 2 Ujoints, 1 on each side, just replace them and you know they're good to go for quite some time. Do go with quality U joints. Don't skimp here. I'd go with Precision or Spicer brand. You'll also have your choice of greaseable or non greaseable. Some prefer greaseable which is all good if you are really going to grease them, and some prefer Non greaseable, not because they are lazy, but because they feel they are stronger since they don't have the hollow voids to carry the grease which does make sense. Precision part # for Greaseable is #377, and Non Greasable is #371 but you still might want to have a parts guy verify that for you.
This is another project, you'd probably want some in person guideance along with patience and a bench vise.
