Well, XAMPP is based on Apache2, so that's what you'd have to read up on.
Hoping you know how to access your site after xampp has it up and running. If not, then this can be your guide http://dslwebserver.com/
And how to setup your site is a variable matter, depending on what the site uses. The best I can say here is, read the documentation that already comes with XAMPP itself. And once you're ready for the plunge, just put the files/folders that are concerned with your site, in the "xampp-installed\htdocs\" folder. (you might want to rename the existing index.htm, and also follow the instructions the XAMPP setup gives, about securing your setup).