I am going to buy a new MTB. I am a long time roadie but new to mountain bikes. I have a friend that owns a shop and he recommends that I get a Cannondale Prophet 600 he also sells Specialized bikes.I would like to keep it below $2000.Any advice would be appreciated.
you have a TON of options under 2k ....go to the LBS and ride ride ride...who cares what it looks like, just make sure it rides correctly. One thing you might wanna establish is if you want a rigid, hardtail, or FS MTB
Getting an idea of what type of riding you would like to do will help you steer you in the direction of a bike. As for your budget, you have plenty of good options, but don't forget all the little add-ons (pedals, shoes, etc.) since they will add up.
If you at a few of the other threads currently being discussed, the FS vs. HT discussion is going strong. If this is your first MTB (as it sounds it would be) I would say go HT. You will develop better skills, get more bike for the money, and have fewer parts to worry about maintaining.
As for the C-dale Prophet, personally I would look around a little more since the Lefty(the front fork/strut) is propratary as well as the hub it requires. This limits options for parts and makes repairs more expensive. Don't take this as C-dale bashing (I own 2) they make a nice bike just offering some fore warning.