I was wondering if anyone knew how to make a generator sort of like this one
http://www.searchbliss.com/banner-ma...ld-banners.htm
Are there any good tutorials out there about making generators like this?

Yes! ...Who that person is, I don't know ;-)

I figured there would be some good tutorials, I just dont even know what to search for.

Here are some great sites with tutorials:

http://www.phpfreaks.com/
http://php.resourceindex.com/
http://www.hotscripts.com/PHP/

You might try browsing around. If I can't find help there, it usually gives me a clue on what to search for.