The map shows all of the visible sky enclosed by the circle of the horizon. By default, North is at the top. It is the view of the sky you would get if you could lie on your back with your feet facing south, the centre of the map being the point directly overhead - the zenith.
In this example the constellation Cassiopeia is almost directly overhead and Pegasus is fairly high in the south.
The yellow dotted line, called the ecliptic, is the path of the sun through the
sky. Of course, if you can see the sun on the map it is daylight and not a good time for observing the stars!
The ecliptic is also the approximate track of the moon and planets. Look along it
in the example above and you will see the planets
saturn and jupiter quite low in the sky in the east. The moon - at around first quarter - is
about to set in the south west.