Even though it's extremely user-friendly, GNOME is a large and complex system, and thus requires some learning to use to the fullest. To make that easier, we've provided some very useful documentation.
Across the world, there are many large-to-small deployments of GNOME, with their specific needs, and system administrators to manage them. Here you will find information on tools and methods to work with many GNOME desktops.
For those who develop, or are interested in developing GNOME and applications for GNOME. You will find developer documentation and information on how to get involved, and much more, in the GNOME Developer Centre.