FAO has recently produced a GeoNetwork Quick Start Guide, which is now available on the CGIAR-CSI GeoNetwork support page. This guide has instructions for first time users, as well as installation and admin help. FAO also created a CD which includes a list of relevant or useful software for the good performance of GeoNetwork. (GeoNetwork v2.0.2 and supporting software for it, GIS & WMS opensource software, etc...).
The CGIAR-CSI has now translated this into French and Spanish.