Dear all members,
I am going to start researching on Geographic Targeting, but was wondering if anyone has any ideas where to begin or how to approach it ?
Thanks in advance…
There are plenty of threads about the topic so I first suggest that you do a search.
Also, the way you phrase is far too vague to be of any assistance. Are you going to write ads for different locations, are you going to redirect viewers as they get to your site when you know where they from? Why do you want to use geotargeting for? 
A look at the following should help you start your research out on the right foot: