Custom Google Map

I am in need of a Google map that I can use on my website [login to view URL] which will pinpoint certain locations of solar resources. I will need to be able to update the resource list myself once the map is completed (you will have to teach me how to do that but I am relatively familiar with html code) and the map will have to include multiple custom icons for the resources I am mapping. Ideally this map will allow users to type in their city or zip code and then see resources near them. I would also like it if the map was fed off of an xml list or a text list that I could publish separately, that way it would be more SEO friendly. I am also open to improvement ideas for this map - generally speaking it should be pretty easy to create, it's just a custom Google map.