We defined a number of terms today:

Celestial Sphere - the sky as seen from Earth
Celestial Pole and Equator - the Earth's pole and equator projected up onto the celestial sphere
Celestial Coordinates - the system for specifying a location on the celestial sphere: Declination - the projection of latitudes into the sky; Right Ascension - the equivalent of longitudes in the sky, but 0 hours R.A. is where the Sun crosses the celestial equator in the spring, and the full circle is 24 hours; the local sidereal time is just the R.A. of the meridian
Meridian - a line in the sky drawn from north to south
Ecliptic - the line the Sun appears to travel in the sky; the projection of the Earth's orbital plane onto the celestial sphere
Zenith - local overhead
Altitude - the number of degrees above the horizon you look
Azimuth - the direction you look (North is 0 degrees, South is 180, East is 90)
Zodiac - the set of constellations the ecliptic passes through
Equinox - the time when the Sun crosses the celestial equator (vernal in spring and autumnal in fall); the time when day and night are of equal length everywhere
Solstice - the time when the Sun reaches its maximum or minimum declination (longest and shortest days of the year)

We saw that the rotation of the Earth causes the celestial sphere to apparently rotate. The basic layout of what you see is discussed further here [1]. The path the stars appear to take in the sky depend on their celestial coordinates, and on your latitude. A more detailed description with pictures is here [2]. Each star or planet has a celestial coordinate; those of the stars are (almost) fixed, while the Sun, Moon, and planets are constantly changing. They change partly due to the motion of the Earth in its orbit, and partly due to their own motions. We saw the day/night cycle, and the cycle of the year. During the year, the constellations that are up in the early evening (for example) keep changing; a given star rises four minutes earlier (solar or civil time) each night. The Sun rises at different times, based on the arc it makes in the sky (whether it is above or below the celestial equator). It is northernmost in the northern summer (at the summer solstice), and the northern day is longest then. It moves 23 degrees north and south of the equator (this is due to the 23 degree tilt of the Earth's rotation axis compared with its orbital plane; we'll cover this again later).

We discussed how all these effects come into the way we keep time.
 

[1] from http://dosxx.colorado.edu/~kachun/sess03.html
[2] from http://www.star.ucl.ac.uk/~idh/STROBEL/nakedeye/nakedeya.htm