how do user permissions work
 

i'm having trouble running kismet and i think it might be a user permission problem. I don't really understand what is a root user. if i install kismet regularly and then run it as root will that cause trouble. when i run it normally it says it can't read the config file, permission denied. Is this a user problem? any insight about users would be greatly appreciated!

"root" is the name of the "super-user"--namely the user that has all powers and privileges, and who sets the privileges for all other users.

Normally, general-purpose applications are set up so that all users can run them. In many cases, the "run" (AKA "execute") privilege is assigned to a group---eg sound, video, CD, etc. In these cases, you simply need to assign user(s) to the appropriate group.

You can read up on users, groups, and permissions in many places, but I would start with http://tldp/org
I would also buy a copy of "Linux in a Nutshell" from O'Reilly