I'm looking to produce a map, similar to this one, hopefully on a free bit of software, like google maps:-
Where I want to show the number value as the size of the circle, centred on a specific postcode. Ideally you'd be able to click through to a
description or hover over for more info.
I can find out how to draw shapes, but not circles?!
Open Street Map can be freely downloaded and customised.
http://www.openstreetmap.org/?lat=-22&lon=-9&zoom=1&layers=M