Thanks much, Nick.
My plan was to talk from Android via Bluetooth to TWO separate Arduinos. Less than 10M will be fine (presuming that 10M spec I've seen in the HC-05 documentation is not super-duper best case). While this is NOT going to be high volume data, neither do I have a need for BLE for this (my first Arduino or Bluetooth project). That said, you never know what other projects the future has in store! 
I do note that you've sent me pointers to three resources. I will gratefully read them all.
Do you happen to know if any of the HC-05 boards are plug in "shields" that already have the resistor divider built-in? (I'm an EE and handy with a soldering iron, but I don't want to have to dink with a production board if I don't have to.)
Thank you very much!