I used to be a former bike messenger and bike mechanic and worked at SYNCROS, that made very high end racing parts. That bike is perfect for a beginner, little pricey, but good. Make sure it's the right size by measuring the down tube, average for men is a 19 inch frame (Mine was a 16.5). What I STRONGLY suggest is getting some anti theft for it from a company called
PINHEAD. I had their equipment all over my $3500 Gary Fisher bike that I hand built from frame up. Put locking skewers on your tires as thieves love taking wheels off with those quick releases, and put one on the seat tube. Also, get a motorcycle U-lock. I could leave my bike locked in DT Red Deer and still have it there the next day. Front tires especially are very stealable because quite often it's the front tire that gets bent in screw ups on the road. EVERYONE I know here that has kids, has had bikes stolen, so PLEASE get anti theft deterrents, and make sure the kids treat their bikes with care. Sorry to be so agro with the theft thing, but a new mtn bike is worth quite a bit to a meth head looking for some quick coin.