Mountain biking the desert environment is a lot different than traditional alpine or forest wilderness. If you haven't had much desert experience, one thorough guide on the subject is The Ultimate Desert Handbook by Mark Johnson. It has nearly 300 pages of information on planning a trip, how to successfully navigate a mountain bike in remote desert without getting lost, tips on clothing and bike gear, avoiding venomous snakes, Africanized bees, and other hazardous critters, first aid, and survival/rescue information. Hey, don't be a statistic!