I'm new to this mountain bike racing thing. I used to race BMX, in which I was a part of the NBL (national bicycle league). I plan on doing the H2H series in 2010. I'm sure there's other races here and there that I will train for, but I guess my main question is- is there some type of league that I need to join first in order to race my mtb? Also, how many miles are the H2H races? Thanks.