Avogadro's Law states that equal volumes of all ideal gases (at the same temperature and pressure) contain the same number of molecules.
Boyle's Law states that equal pressure is inversely proportional to volume (when temperature is constant).
Charles's Law states that volume is proportional to temperature (when pressure is constant). Remember that temperature must be measured in Kelvin.
Gay-Lussac's Law states that pressure is proportional to temperature (when volume is constant).