For shock servicing including having the following mod done professionally, and revalving services, check out the revalve/rebuild page here.
The most basic shock mod that you can do is high volume nitrogen caps. The factory caps use pellet valves and are known for leaking the nitrogen pressure out. Some guys have reported their nitrogen leaking completely out. Proper nitrogen volume and pressure will improve the ride quality. Terry Hatfield has a great video on how to replace the caps. It only requires some simple tools:
Pick set ($5 at Walmart if you don't have)
Flathead screwdriver (helps, not required)
Cleaning rags / cleaner
O Ring lube (I used thick silicone grease)
My favorite caps are the NRP high volume caps, you can order through several vendors and should cost around $150 for a full set. These are identical to the Schmidty Racing ones. The best vendor I found for these was TeamFAS Motorsports ($140/free shipping), you can find the caps here: NRP High Volume FOX 2.0/2.5
Unless you happen to have nitrogen filling equipment, you will need a local tire shop or bike shop to fill them. Tire shops will not likely have a no loss chuck system, but you can purchase one from Schmidty for fairly cheap to go with your machine. Check it out here, it will be a Type U 300psi that you need to order: Schmidty Racing No Loss Chuck with Gauge. And finally, here is a list of known places you can get a nitrogen fill if any happen to he in your area.
There are 2 things you need to keep in mind when doing your nitrogen fills:
When doing your initial fill, the air needs purged out. Just fill to 100psi, and use the chuck tool to drain it out, do this twice.
The shocks need to be decompressed while filling, if they are on the machine you'll need to simply jack it up off the ground.