+1 for Webmin
OK, I'm never going to be a paid Linux sysadmin. But when I started dabbling with Linux, about 5 years ago now (slight pause for that to register) the one tool which I stumbled across which transformed my experience was Webmin.
Despite being able to remember DOS 2.0, I am unashamedly a GUI fan. My argument is a *good* GUI can help enforce some sort of understanding of what's going on underneath - a classic example being an input field that is greyed out unless a checkbox is ticked. The GUI shows you the relation between the two.