PHP/MySQL: Create dynamic navigation/pages

So, I've been experimenting with this for a while now, and I just cant get it.

I'm trying to write a script that uses dynamic pages, like wordpress:
EG: http://site.com/dir/page, where /page is not an actual directory/page
and the content on that "page" is from a database


any suggestions or tutorials?

any suggestions or tutorials? Do you know how to make a CMS without such pretty urls?

@abduraooft: no, i do not. that's what I'm trying to learn

Well, to some point actually, I know how to write the cms (blog, control panel, etc) but just not that little part.