Which city? I'm assuming Philadelphia....
the hardest part is deciding on your first bike......
Basically.... there are 2 main decision points:
Hard tail vs Full Suspension
26" vs. 29er.
(third is frame material).
Hard tails have a shock in the front fork and Full Suspension, as you would guess, have a shock/spring for the rear wheel. Full Suspension costs a lot more (not referring to cheap Wal-Mart, Dick's etc bike).
The bigger debate is 26" vs. 29er. Both have its pros and cons and followers of both types.
Here's an article to get you started
http://www.mbaction.com/Main/News/Sh...s_26_5159.aspx
A popular bike last season on the 29er side was the Trek Marlin.
http://www.trekbikes.com/us/en/bikes...r_sport/marlin
My bike, when I bought new a couple years ago.... cost $1000, with nearly the same equipment levels... so 29er prices gone down a lot....




That was my first mtn bike, it was a hell of a lot of fun.
)