This map should be pretty easy to understand. The mountain along the western boundary is Mount Mindolluin, and the city of Minas Tirith is built up against it.
Minas Tirith's port Harlond lies to the south of the Rammas Echor, which has three gates (two running with the north-south road, and a third leading to Osgiliath). The main city is surrounded by the Great Gate, which was destroyed by battering ram during the Battle of the Pelennor Fields.
The longest river on the map is the Andúin, flowing through Rohan in the immediate northwest. The river that joins it from Mordor is the Morgulduin.
Much of Gondor proper lies southwest from this map, but Minas Tirith is its most sensitive location for its proximity to Mordor (which lies just east of Ithilien on this map). By the way, where the map is labeled 'Gondor' is accurate, but might more specifically be labeled 'Anorien.'