WordPress MU

Hello guys. I have a fresh wpmu installation and just want to know if it is possible to add another category besides the default category "uncategorized" via the mu code. I want to have 5 more categories included by default every time a new user creates a blog. Maybe it is editing the wpmu-functions.php file, but I'm a newbie and don't have the needed php knowledge to do this, so I really need some help. Note: Should I do this editing before the wpmu installation? If so, I'll install it again. Thanks for your consideration :-)

http://wpmudevorg.wordpress.com/project/New-Blog-Defaults

Thanks Mercime. I'll check this one.