I think mod_include is distributed with Apache. Check your httpd.conf if it is commented out (with a leading #). If so, remove the # and do an Apache graceful on the shell.
I don't see your confusion with permissions. You hop on a shell and chmod to whatever you need. For example, chmod +x to make a file executable. Also have a look at chown and chgrp., and their designated man pages.
Cheers,
Till
P.S.
Want to put your steps in a small tutorial?