New project, not sure where to start!

Hi guys,

 I've got a new project to work on and to be honest not sure where to start.

I've been asked to make a map with each county showing, when you click the county it expands, once its expanded there is a drop down box which has different products to select. When you click on one of the products the county shows dots of companies in that area that sell that product, if you click on one of the dots it then shows that companies information.

 I have no idea, is this a mix of flash with xml or jquery or sql?!?!??!

 Any ideas?
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