play around with this: http://sheldonbrown.com/gears/
and try to find something as close to 70 gear inches as you can get IMO
if you're riding brakeless, than its best if you have a gear ratio that cant be simplified (i.e. 46/17) so you have enough skid patches to not wear your tire out too quick.
as long as you get the weight up front and lock up your rear leg, which should be your strong leg, than you should get it. it takes a little bit of practice. and a little speed makes it easier as well