You might try a GIS like QuantumGIS, uDig, or OpenJUMP.
GIS is the tool used to do this sort of thing with REAL geographic data and so can handle things like varying visibility and symbolization with scale. (So as you zoom in layers can appear, disappear, or change their appearance) It is NOT just a fancy graphics program though, in fact it is very, very different from graphics software. The maps you get out are not meant to look pretty, they are meant to be functional. If you want to make them pretty, you can export to an image and edit it in a graphics program like Inkscape. Also the entire conceptual model and the way you do things are quite different.
You can even load your GIS data into a WMS server like MapServer or GeoServer and have a scrollable, zoomable web map like Google Maps or Open Street Map.

