Kinetic Molecular Theory - Know the assumptions involved in KMT. The gases that can be modeled with KMT are called "Ideal Gases." These are pretty good approximations of any gas under normal conditions (i.e., not too high pressure, not too low temperature, and not too small volumes).
Pressure units - Atmosphere, Torr, millimeters of mercury. How do these relate? What are the conversion factors?
PV=nRT
This is the equation you should know cold. Memorize it,
play with it, manipulate it (algebra: solve for each variable),
and use it often in examples. It's all you need. Know how
the other laws can be derived from this. Remember, to derive
Boyle's Law, just put P and V on one side, and know that
everything else is a constant. Hint: You should also know the
ideal gas constant (and it's units). From its units, you
can get the ideal gas equation, or vice versa.
STP Conditions - What temperature and pressure?
How can you use PV=nRT to determine the molar mass of a gas?
What about gas density?
Partial pressures - The total pressure of a mixture of gases is equal to the sum of the partial pressures of the individual gases. This is because all gases in the mixture behave the same as each other, and the total number of moles of gas is equal to the sum of the moles of individual gases. Moles are directly proportional to pressure. If you increase the number of moles of gas in a container (while holding the temperature and volume constant), the pressure increases.
Collecting gas over water. You should know how to use a table of partial pressures for water at various temperatures, to calculate the amount of gas collected. This type of calculation can be combined with a stoichiometry calculation.
Know how to calculate and use the molar mass of a gaseous compound. Also: know how to calculate and use the density of a gas.
Gas stoichiometry - It's chapter 9 all over again, but now you get volume to moles conversions too. Just use PV=nRT, as usual. And remember, to use the coefficients in an equation, you have to go moles-to-moles.