where to find tutorial

I have some very crude scripts that I have mangled together to allow customers to request CSR call-backs when they want new service. I am trying to make the page more user-friendly. I have three fields that I want to try something on and don't know where to look. I have a city, state and zip code field. I only need two state entries and about a dozen city/zip entries. It will likely never increase beyond this. What I want to do is to allow someone to select a zip code and the city and state fields automatically change appropriately - and visa versa on the cities. All three fields are pulldown menus currently pulling from includes but can easily be put into a mysql database if needed. I am dumping the data from this form into mysql right now. Anyone know of a tutorial to do something similar to what I want? I am not a programmer but can hack my way through things pretty well. thanks, Doug