Detour paragraph - background - Internet has historically been pretty sht in South Africa so a enthusiast spider network of point to point links sprung up much like the ham radio movement. Government decided to OK it as long as its not commercial & doesn't deliver internet services.
Anyway...the WUG websites (JAWUG, PTAWUG, CPTWUG - being Johannesburg/Pretoria/CapeTown) have lots of beginner style info on it (will trees and leaves in block it etc)...plus info on cheap kits...plus there are loads of people there that know this stuff in wild detail (as I said - 100% community driven so even the central high-sites are community run).
The company's community forums can be quite helpful too.
What kind of link are you after? (Speed, distance, how far over water, are both sites powered, etc)