on the left side of the admin page there are all the top level menu buttons such as users and settings.
I want to make my own plugins page that is more indepth than the custom page but i need to look at the source code inside of wordpress.
where is the file for the plugins page inside of wordpress 3.4.1? (newest version)
I think this is what you are looking for:
From the WordPress root: /wp-admin/plugins.php