Whenever I get a new pin I just play it for a few days just to take note of anything that's not working properly, or doesn't look good, and I make a list of things it needs, or upgrades I want to do. I'll keep playing it while I'm waiting for whatever parts I ordered off the list I made.
When parts arrive I tear the top side of the playfield down for a deep cleaning (leia's beard), polishing and waxing. While it's apart I get familiarized with everything (mechs, switches, ramps, plastics...etc), and clean each part I took off before I reinstall it. When everything's spic-n-span is when I install new bulbs, rubbers, and piece everything back together. This is also when I'd remove all of the lamp boards, and reflow solder on the connections.
I also install a lithium battery board in place of the AA's (or NVRam). Check all the fuses to make sure they're the right value, and that the holders are still in good shape. Check the boards for corrosion, and old bulging caps that may need to be changed.
I believe it was a fellow pinsider Mof that posted a really detailed checklist he goes through for each pin he works on. It's a very thorough list that covers everyting.
I guess it's all dependent upon what you're really looking for.
Congrats, and enjoy!