OK, you'll have to separate this project into two parts:
1) the mouseovers / clicks / image changes. This part shouldn't be that hard. Just google for "javascript mouseover image changes." There are hundreds of tutorials out there...

2) the CMS. This will be a bit more complicated. You're going to need to use a server-side language like ASP of PHP and you'll also probably need a database. I'd suggest opening a new thread in the ASP or PHP forum if you have more questions about this aspect.

Good Luck, feel free to keep askin' and we'll do our best to help out...