Its going to depend heavily on the type of offroading you are planning on doing. If you are into rock crawling your needs will be very different than if you are doing trails at an OHV park or fire roads through a national forest. The advice given above is solid, but depending on your budget, rims and tires might be a bit of a hefty output of cash after buying a nearly new truck (I still can't afford 2006 models

). Another option, the one that I used myself, is to set up a basic recovery kit (hi-lift, chains, recovery straps, first aid kit, etc) get a friend who has a 4x4 and some wheeling experience (in case you need someone to pull you out or lend a hand with something) and hit the trail. This is of course assuming your stock tires are at least All Terrains (not a pavement only tread as some came with) and have some decent tread left on them. Bottom line is to get out and drive the truck the way you intend. As long as you ensure your own safety, the truck will tell you what it needs to do what you want it to do. The strengths and weaknesses will become apparent very quickly once you get out and do some driving. Have fun and be safe out there.