Changing permissions with usernames on LINUX

[linuxtricks]

Hi all. I have set username standards on our network some time ago. We have this setup on the NT side and I would like to duplicate the same standard on the Linux side. At this time most usernames on these (Linux) systems are in a standard of just the "first names" of users. I would like to change this standard to "first initial + last name".

My question is: Will just renaming the username change the permissions on files and directories pertaining to that user?

Basically, we would like to rename a username and have their files and directories reflect the new username and permissions for that username.

Does anyone know of an easy way to do this? I hope I do not have to manually change permissions throughout the system?

Thanks in advance for your support! I HATE BEING A NEWBIE!
-grumpy smurf