What Hokie said...
The hydraulic fluid is not required on my L3800 until 400 hours. Every machine is different. Check your Operator Manual to verify for your specific machine. While you are down at the dealer buying engine oil filters and the one or two hydraulic filters specified by your service interval, grab the SUDT fluid you'll need for later. You can get it online but the shipping is expensive. If you dealer is close, it can wait. The synthetic fluid is expensive but you don't do it but every few years. The only thing odd about hydraulic service is you drain the main sump and then go around to several lower drain points, to drain them as well. Not hard, just a few more things and a potential for a spill. Have lots of cardboard underneath your work area!
I have found almost nothing online that beats my dealer price.
A tip for fuel filter service is pinching off the fuel line that comes down out of the fuel tank. Most machines don't have a fuel shutoff valve so a nylon hose pincher or a Vice Grips gently squeezing off the hose to at least a slow drip gives you a second to pull the bowl, wipe it clean, pop the new element back on and then screw the bowl back on. This is a messy job because the bowl is full when you remove it. More cardboard and a bucket would really help. One tip I have heard is to get the element in the bowl barely started back on the threads so there is a little air gap to let air out. Unclamp the fuel line and let the bowl slowly fill. Then, right as it fills completely up, spin on the bowl and hand-tighten. Don't over-tighten the bowl. Leak check it afterwards. This method prevents having to "burp" your injectors due to introduction of air.
Tractor service is pretty easy as most of the service points are easy access. The Owners Manuals lead you through the basic service steps.
Ray