The best shop manual is the Helms manual.

If the joint itself is still intact and the noise is from lack of grease due to a split boot, then you can get away with replacing just the boot. If the joint is shot, it's best to replace the entire axle.

Generally you should do both sides at the same time as a precautionary measure. It should be less than $100 to pay a shop to do both the boots, usually places like Meineke, Midas etc will have some kind of deal going.