Arizona is well known for it's dry, very rocky terrain. A lot of people out here ride full suspension because of the comfort factor, but there's also a group of folks who prefer hardtails, and even rigid bikes. Bring the bike you are most comfortable riding and plan on having FUN!

We live in a desert - there are cactus everywhere. Every trail here has spots where your chances of running into something sharp are really good. Staying on the trail is the best way to avoid being stuck, obviously, but if you do get stuck and they stay in you - DO NOT try to pull it out with your fingers. I carry a cheap black plastic comb in my pocket that I use to pry cacti off myself with, it's a good investment.

WATER - and something big to carry it in. It's dry and warm out here, you will dehydrate much faster than you think. Drink and caarry plenty of water.

Pads - If you're not used to falling on rocks and other sharp objects, pads are a good idea.

Slimed tubes - a lot of us don't used slime in our tubes, but we also know the trails and how to avoid the cacti. They're a good idea if you don't want to change flats, if you don't mind - don't worry.

Tires - Because it's dry, just about any tire will do. The bigger ones will give you a smoother ride over the rock and bumps. I use a 2.1 Tioga Factory DH in the front and a Velociraptor in the back. Works fine for me.

You've all heard stories of rattlesnakes, scorpions, gila monsters and other desert creatures. Don't be afraid, most snakes and such are more afraid of people than we are of them. 

One of the anti-venin centers in Tucson did a study which showed that by far the highest percentage of snakebites were to drunk males in the face, arm and neck. Think about it - picking up or chasing a snake is the best way to guarantee you get bit. If you see one that seems agitated, back away from it and keep your bike in the middle - better a snakebite flat tire than a trip to the Urgent Care Center.

Scorpions are hard to see and easy to avoid - just make sure you shake out your helmet and shoes before you put them on.