Hi,

The percent sign (%) at the start of the line signifies that this is a UNIX group name, and not a username. So it will affect all members of the group called unixforum, and not simply one single user. Lines without a percent symbol would affect only individual users and not groups.

The point of the sudoers file is to specify commands that users can run, not to list all the files or things they can access. So putting the sudoers file itself in the sudoers file doesn't actually make any sense. You also missed out the space between the colon and the command list, which may be important in your implementation.

So, if you wanted to give the user james permission to use sudo to edit the sudoers file, you'd actually want a line like this:

james ALL=NOPASSWD: /usr/sbin/visudo

It's worth pointing out that this isn't actually a good idea at all. Letting a user edit the sudoers file themselves via sudo is very dangerous and not at all secure, since they could then give themselves permission to run anything at all. If you're going to do that you might as well let the user run any and all commands without a password, since all you're really using sudo for at that point is to get a passwordless su.

Hope this helps.