Map dialog
A map dialog is available in FlightGear. You may be looking for Atlas, which provides high-quality digital charts via a separate application, or the multiplayer map, a Google Maps overlay displaying similar data.
Introduction
The map dialog aims to provide a visual representation of navigation data in the simulator - i.e airports, runways, navaids, and so on. It does not display any geographical data (borders, coastlines, roads or rivers) at all, though support for basic borders and coastlines may be added in the future. Multiplayer traffic can be shown, and in the future airways, obstacles and other object types may be displayed. Data can be shown about items in the map, such as the frequencies of a navaid, or the length and bearing of a route leg.
Aircraft information is also shown, notably the current ground track (derived from the GPS) and heading. Optionally, the map can be orientated so that the aircraft heading points upwards, allowing the map to be used as a crude generic navigation display. (Some of the symbology and colours used are intentionally similar to a Boeing ND)
Usage
Make sure you see the menu bar (F10 to toggle). Open menu "Equipment" and click "Map".
Drag with left mouse button to pan the map, and use the mouse-wheel to zoom in and out. You can also pan using the cursor (arrow) keys, and zoom using the +/- keys. Control-click to place a marker point - a line (in cyan) will be drawn from the aircraft position to this location, and the distance and bearing will be displayed (and updated as the aircraft moves).
The tuned VOR(s) and their selected radials and range-circle will be displayed (in cyan), assuming the aircraft is within range of the station. When tuned to an ILS, the corresponding localizer will be displayed in cyan instead of blue.