Jim,
C++ is a bit difficult to grasp compared to other languages, mainly because sooner or later you have to deal with understanding memory, pointers, bytes, bit logic etc. This is especially true for embedded systems and Arduino (pretty much anything other than blinking LEDs...). The examples I posted along with the RFM12B and RFM69 libraries are meant to cover the most general of cases where you might want to send data as clear ASCII text or as structs, or just send some signals back and forth. They are basic examples of how to initialize and send data with the radios. These examples will of course not cover every possible scenario everyone needs. I will add more examples as they become available.
Basically the 'payload' is an array of bytes (really just a pointer to an array). You can dump ANYTHING in that array.
If you want a single byte value (0-255) then just dump that value in the first byte of the array:
If you want characters then do something like:
payload[0]='a';
payload[1]='b';
payload[2]='c';
and so forth.
Unfortunately developing any type of code will require a little more than copy pasting. But the good news is we're all in the same boat