Code Website from PSD File / Google Maps API Interface

I have a website for an outdoor website I am designing. The company sells billboard space, so I will need to have a Google API interface for the maps portion of the site. It's extremely important that the Google Maps part of the site has a very easy way for the back-end users to upload/update information about the locations. The site needs to have a very easy back-end. I have examples of what the drop down navigation menu needs to be. A very simple set up for a drop down. Probably done in Javascript. I've built the website in PSD photoshop format. You will need to code this website as well. Any kind of CMS would probably be a good idea as well. ## Deliverables We would like to have the navigation menu at the top done in Flash. Reading the navigation items off maybe an XML file or something. The Google Maps API must me ***as easy as possible*** for the back-end user to operate. This is essential as everyday users who work at this company will be adding locations, and they will most likely have zero experience in programming or web design.