Custom Post Type Geolocation/Taxonomy Search

A non-profit organization I volunteer for is wanting me to add something like the search functionality from http://www.eatwellguide.org/. They have entries similar to those on the Eat Well Guide’s website stored in custom post types with geolocation data. I’m not sure how to accomplish the search functionality being used on http://www.eatwellguide.org/. Can anyone point me to the correct resources/information to get me started? I’m not even sure if I’m asking this in the right forum…