Since we dont have a crystal ball to look into the past (if we are the second/third owner) or the future, preventative care should be the foremost concern.
Schedule change of oil.. I go every 3000 religiously since I bought her new). Checking that oil stick in between oil changes. I keep a real close maintenance eye at the PCV and EGR and perhaps the MAF.
For the good of the members, is there anything else that should be included?