> Sorry I did not include what it is giving me.
> rob@fearlessrogue:~$ su
> Password:
> root@fearlessrogue:/home/rob# cd /
> root@fearlessrogue:/# chown rob.rob /stuff
> chown: changing ownership of `/stuff': Operation not permitted
> root@fearlessrogue:/#

Syntax should be

chown owner:group directory

Looks like you just need to change the '.' to a ':'.

>> What is the commmand to change ownership of a directory on the command
>>  line? the man page for chmod is not very helpful.
>>
>> I am trying to make a guest user account that would rx access my
>> music,  but no access to my email and such...

An easy way to do permsions is
+ is add
- is take away
= is stay the same

u is owner
s is group
o is others
a is all

r is read
w is write
x is execute

You want some one else to be able to read and execute your music so do..

chmod o+rx musicdir

do an ls -l to verify

-Derek