how to find city and or zip code search like groupon.com

Hi,
I need to have custom fields, post types and taxonomies for my wordpress website, I wanted my website look like groupon.com or livingsocial.com, they also have a Geo search plug-in (when you type the zip code or City name, it show up all contents for that City) can you tell me what is the name of their plug-in, if this is not a plug-in what is this? how can I find this?

Note: Question number 1 is what is the name of Geo Search plug-in that groupon.com used
Question number 2 is one on one online tutorial for custom field, post types and taxonomies for wordpress website, which online one on one website you recommend
Thank you for your attention
Don Lee