In the Space Setup > Dashboard > Content tab, you can control the sections that appear in each Space's dashboard tab. You can also revert to the default that is determined in Server Setup > Defaults > Space Settings See Sections Overview for more detailed information on the section settings.
In the Display subtab you can over-ride the Dashboard's display name and title.
In the Space Navigation Links sub-tab you can add a set of links in the right column (up to version 4.2 - or enabled via plug-in in 5.x and later) and you can manage the Root Articles which form the top level Table of Contents.