Let people know where you're going, times and whatnot just in case.

Search for what to take:
http://www.xterraownersclub.com/cgi-local/ultimatebb.cgi?ubb=get_topic;f=7;t=000297

Besides the common parts, tools, supplies, gear, food, water, etc nice to have communications devices like a CB, HAM, cell phone, etc just in case you need to reach out and a GPS to keep on track.

Winch, jacks, straps, shovel, recover gear can go along way in getting you unstuck

Other than that its more enjoyable to have company outdoors