Serializing/unserializing objects

What I want to do is to use an object to create a site.I plan on initiaizing the object on my page index.php, and just recycling index.php with different variables, so that I get different pages. Ideally, I want the object to read a site config file, so that I can modify the site config file for different sites which use the same backend, and have each sites page read that. What is the process of object creation in php4? What happens when you call new objectname? Where could I find this out (short of reading the source - I need to do this by tomorrow...)