Buy an MTB yet? I'd be interested to see what you bought and the why's of your purchase. If not, I see that you are in a rocky and sandy location. If you are in the desert southwest or an equally "rugged" location with plenty of ups and down, I would steer you toward a full suspension (FS) MTB. The terrain is just too unforgiving for most anyone, nonetheless a beginner, in my humble opinion. The brand is not as important as being happy with your purchase. You will spend near $1000 for a good quality MTB though you could find last years model at a good discount. You need to pedal around the parking lot or even rent a bike to see what works for you. What's important in a FS MTB is the "bob" effect of the rear suspension. Duriong pedaling on flat or uphill surfaces, the bike will "bob" up and down during the pedal stroke. Good bikes are designed to limit this "bob" either by design or with an adjustable rear suspension that, with a flick of a lever, can limit or turn off "bob". You will be very satisfied with any of the major brands on the market. Stick with a local bike shops or go to the internet if you know what you are looking for. Many off-brand bikes use the same geometry and suspension from major manufacturers (horst, DWlink, and others license out their designs) so you can get an MTB priced well below name branded ones. I test rode at least 10 different brands (Trek, Cannondale, Specialized, Yeti, Giant, Santa Cruz, Ellsworth, and Intense before settling on a Turner Burner). If you aren't in a rugged area, I'd go with a hard tail with a nice front suspension fork. FS bikes have limited application in nice rolling, root strewn, sandy areas that aren't covered with the crazy rocks and descents we have in the desert southwest. Plus, FS bikes are heavier. Overall, the benefits of a FS bike in terrain not necessitating FS goes largely unused. For your height, you might consider a bike with 29" tires. Your height would work well with the larger tires. Again, you have to test ride to find your bike. Be confident that your local bike shop (LBS) won't sell you a bike that isn't your size- they want your business when it comes to word of mouth and maintenance. Try different sizes too. A Cannondale x-large might fit you better than a Trek large. Also, you can size up your bike, but not size it down. By this, you can swap the stem and adjust the seat post to size the bike to your height and reach. But, if the bike is too big, you will have to suck it up. Don't ignore used bikes either. Check Craigs LIst; folks are looking to sell their bikes on this free on-line community. Ask the seller to have your LBS check it out first. If you buy from the internet, your LBS will usually assemble it for a nominal fee- well worth the cost for someone who doesn't know how to adjust the brakes, cable, gears, etc...
