All users have access to the Manage Reports tab. On selecting the Manage Reports tab, the left pane displays all the folders you have access to. When you select a folder in the left pane, the Dashboards that belong in that folder are listed in the middle pane. Selecting a dashboard displays the sub reports of the dashboard on the right pane.
The options available to you at a Dashboard level and at a sub report level depends on whether you are the author of the dashboard or have editor or viewer privileges to the dashboard.