Hello,
 
Can anyone recommend some good online tutorials, on how to effectively interpret and utilize an Audio Phase meter.
 
TIA.

Pop one up on your screen whenever you have visitors, as they will be impressed by it.
 
Beyond that, they're rarely used except for a quick check when you hear problems with mono-compatibilty, or just want to reassure yourself that you're getting a nice, wide mix with satisfying L/R balance. 
 
Here's an article that touches on the subject (scroll down to "Goniometer"): http://music.tutsplus.com/tutorials/why-you-should-use-metering-tools-while-mixing-and-mastering--audio-12470
 
 
 

It is fun to have one on screen.  It works on the odd occasion where something may sound mono or off center and you want to know if it is the file or your hardware.  It can also let you know if/or what type of dithering is engaged from a plugin if you can't remember.  
 
But mostly for the looks, meters do impress clients.