Are you trying to add to the admin cp or to the usercp? Because you kind of negated your title with wanting to add to the usercp. If you're trying to add to the admin cp you can add the links in the admincp/index.php file and then create the php file using
PHP Code:
print_table_header ( ) ;
etc.
If you're trying to add a section to the actual usecp then you have to edit the USERCP and USERCP_SHELL templates and then add the php in the profile.php and create your own templates using vb's template system and don't forget to add the templates to the $actiontemplates global variable to save query usage.
Hopefully that helps somewhat.
Cheers,
g-force2k2