Database search/user management site needs expansion

I have an existing, functional php script/jquery which searches a mysql database, based on a user's zip code, and the zip code listed in the database, and then displays the results utilizing google maps (similar to a store locator). Right now, the script searches one table in the mysql database. I need the script to be expanded so that it can search multiple categories (33 to be exact), thus multiple tables (or however you want to organize the database for speed and efficiency). I also have a functioning script that allows users to create an account, and add listings to the above database. I need that to be expanded so that they can choose which category they wish to add to, and also add the ability to upload an image. The user also has the ability to view and edit their listings. In total, there are around 30 php files that will need to be updated. You will be working with mysql, php, and javascript/jquery.