Check out Fewmiles' Unofficial oneworld info desk at
http://fewmiles.tripod.com/oneworld/index.html#1
It will show updated prices for many countries. To book it just call BA and ask for the RTW desk. They can set it up and as Darren already said you can pick up the ticket in the country your ticket starts. Just make sure you have some time as printing these tickets will take some time.