Preventive maint. is the key with any machine, Jeeps are no different. Like Jsuggs said, the owners manual has all the major info for intervals, fluid specs, etc you'll need. You can pick up a Haynes manual, for about $15 on ebay, that has all the detailed info you'll ever need, and in the event that you need more, between this forum (and others), a call to a local service section of a stealership (you'd be surprised how friendly mechanics can be if you just go down there and pick their brains), you will be covered. I am no mechanic, but short of tearing down an engine or tranny myself and rebuilding it, there's not much I haven't been able to figure out with some help. No doubt I could tackle those as well with proper planning and the right tools and some experienced help at my side. Short of exhaust manifold cracks, the I6 4.0 is one of the most solid engines I've ever seen, and I hear the same from mechanics and do it yourselfer's all over the place.