Attached is a presentation from Airheads Vegas 2012 and Airheads Bangkok 2012, summarizing 802.11 basics. An earlier version was also presented at Airheads Dallas 2011.
For more details, take a look at the 4 part online video series on RF fundamentals below.
Components: Transmitter, Antenna, Receiver, Isotropic Radiator, Intentional Radiator, EIRP
Characteristics: Amplitude, Frequency, Wavelength, Polarization
Behavior: Wave Propagation, RF Power, Path Loss, dBm vs. mW, Absorption, Reflection, Scattering, Diffraction, Multipath, In/Out Phase, Attenuation, Amplification
802.11 Overview: 2.4 and 5GHz channels, 802.11h (DFS & TPC), 11a/b/g vs. 11n, MIMO