The thing is, I would really like to learn RF,
Then that is a totally different story to playing with an Arduino to remote control a car. Most of us that play with "RF" are really just using normal digital with somebody else's RF modulator gadget and we don't know how it works. (OK I'm speaking for myself, but I'd say that's the case for most embedded/uC people).
I'm sure there are some RF guys here, but maybe there's a more RF-oriented forum out there.
Rob