I'm not sure if this is a very good idea. I'm physically unfit. I've never been too keen on changing this in the past either. I don't own a bike. I am terrible at estimating distance. I don't like the idea of wearing a helmet and I know I won't look good in one either.
I still think it will be good though. I like a challenge and I bet it will be a lot of fun once I've done some training and all that. I'll have the added bonus of getting myself a bit healthier too.
As for the issue of not owning a bike I'm trying to pick up a bargain second hand off ebay. I'm the highest bidder on one at the moment but its still got a few days left on it. I want one now so I can go out and get practicing. also, once I have the bike I can start buying all the cute bike accessories.