I am new to this forum, and joined to hopefully get some helpful information on radio wave propagation from antennas.  

I have had very limited previous experience 2 years ago with antenna propogation, and would like to know if anyone can explain or direct me to a place that can tell me the mechanics of how radio waves propogate from antennas depending on the antennas setup (among other things).

I will be making an antenna within the next while, and haven't decided if I want it an omni directional or a directional antenna.  My first step will be learning the basics of how they work. (and in what direction they best transmit in depending on their configuration, why wider antennas are better, calculations, etc).  Any and all help would be greatly appreciated.  Thank you!!