Setting directory permissions right

[Proteus]

Hi!

Can anyone tell me how I can set the directory/file permissions for my system the right (secure) way?

I want it that way that no one but root can danger the system by deleting/editing files. So no standard user can do harm to any files but his own.

Of course I could set all files currently present on my machine "root only" and then start adding new users but I am not sure if that would break anything....
_________________
Greetings,
Proteus

[sa]

mabey this will help?
http://gentoo.org/doc/en/gentoo-security.xml