This is a MUST DO for anyone visiting Vegas. It's so much fun, I can remember having a non-stop smile the entire day, even for hours after the tour was over.
The ATVs are very easy to ride. Pretty much anyone who is able-bodied enough to ride a bicycle or horse will be fine on the ATV. The staff is great & will teach you everything you need to know to have a safe, enjoyable trek in the desert. The scenery is a beautiful mix of desert landscape & mountains. Be aware that you get very dusty, so dress appropriately (jeans with a light jacket & covered shoes).