su Usage

[WipeOut]

Can somone point me to a good doc on using "su"..

I have always just logged in a root because security was not really an 
issue, but now I need to operate in a more secure fashion as far as user 
account controls are concerned so the starting point I feel is to not 
allow root to login directly with ssh..

This means I have to get to grips with the ins and outs of "su" but the 
man page is a little shy.. anyone got any useful info?

Thanks..