Polish an aspx page written in 2003 and fix programming

I have a website written in aspx that is used by very few people right now, and I know the reason. The coding needs help. It was written in VB 2003 and the programmer slacked on polishing it off. I need the program polished off. I'll send you the websites url upon request of the project so you can understand what i'm about to talk about next. What is the websites job? Pulling up Tax data and property records for clients in a single state. It's all written in aspx and it refers back to a home database i have purchased for the site. It pulls up all the tax data fine but it does not associate the correct tax map with that address. I need a way to geocode tax maps to those address that people search for as well as the site being polished by a professional up to date aspx programmer. It has its flaws! What exactly i need done? Site Polished (it was written in 2003 i want it up to date with 2014 language) Geocoding tax maps to property address. Something like a google maps and when they click on a block and lot it pulls up a certain image, being a tax map i have for all of the state)