Know formulas:
Kepler's 3rd law
Newton's law of gravity
parallax distance
luminosity depending on radius and temperature
Be able to use (no need to memorize but know concepts/proportionality):
magnitude difference <-> ratio of luminosity
small-angle formula
energy of a photon
speed = wavelength * frequency
Wien's law
Stefan-Boltzman law
Doppler effect
constellation (remember it's 2-dimensional)
moon, planet, star, solar system, galaxy, Local Group, cluster of galaxies, universe
twinkling of stars (point sources) and "seeing" of telescopes
celestial sphere (poles, equator, ecliptic, inclination, precession, zenith, horizon)
seasons, equinoxes, solstices
perihelion, aphelion, perigee, apogee
sidereal vs. synodic period of moon and phases of the moon
cause of the tides
lunar and solar eclipses, total vs. partial vs. annular
possible causes of the ice ages
geocentric vs. heliocentric, retrograde motion, epicycles
Kepler's Laws, Newton's Laws, what each of the big guys did
inverse square law for light and gravity
reflecting vs. refracting telescopes
light-gathering vs. resolving vs. magnifying power
active optics vs. adaptive optics
sound waves vs. electromagnetic waves
atom, nucleus, electron, proton, neutron, molecule, isotope
ionization, energy levels, ground state vs. excited state
blackbody radiation (continous spectrum) vs. absorption lines vs. emission lines
differential rotation of Sun
prominences vs. flares vs. sunspots
apparent vs. absolute magnitude
H-R diagram, main sequence, dwarfs vs. giants (luminosity classes I-V)
spectroscopic parallax
visual vs. spectroscopic vs. eclipsing binary