Installing a gui won't offer much assistance when dealing with smb, However it would allow you to manage shares through a graphical point and click means.
Some basic commands for managing users and groups.
adduser (adds a new user to the system)
deluser (deletes user)
passwd username (changes or adds a password for user)
groupadd groupname (adds a new group)
groupdel groupname (deletes group)
useradd username groupname (adds a user to a group)
--- Taken from oreilly.com ----
220.127.116.11 Removing a member from a group
Unfortunately, no command removes a user from a specified group. The easiest way to remove a member from a group is by editing the /etc/group file. Here's an excerpt from a typical /etc/group file:
Each line in the file describes a single group and has the same form as other lines, consisting of a series of fields separated by colons (
. The fields are:
The name of the group.
The encrypted password associated with the group. This field is not generally used, containing an x instead.
The unique numeric ID associated with the group.
A list of user accounts, with a comma (,) separating each user account from the next.
To remove a member from a group, first create a backup copy of the /etc/group file:
cp /etc/group /etc/group.SAVE
The backup can prove helpful if you modify the file incorrectly. Next, open the /etc/group file in a text editor. Locate the line that describes the group and delete the user name and the following comma, if any. Save the file, exit the editor, and check your work.
---Taken from oreilly.com END -------
you may also be able to use smbstatus to show what shares are available and who is accessing them. However, this is not always installed.
Here is a link to the oreilly.com book the section above is pasted from