Creating Drop Downs

Hi,

I'm sure this has been answered many times before so if someone can point me in the direction of a thread that answers it I'd be greateful.

I'm creating a site for a holiday home company so they will have properties from many different locations.

I therefore need be able to add new locations in CMSB and when they add a new property I want them to be able to select the location from a drop down in the editor.

Hope that makes sense !