Tutorial on user and group management in Linux?

Solution 1:

This isn't the most fancy way of doing things, but I mostly just use VI when editing these things. Of course, I use useradd to create a user. But then I'll use vi to make changes.

For Ubuntu, I found a reference on how to manage users.

I don't know if Ubuntu has this command, but in Red Hat/Fedora and related distributions, there's a command system-config-users which is pretty self-explanatory.