I suggest that you try the simpler examples in Robin2's simple rf24 tutorial.
If you read and, closely, follow Robin2's simple rf24 tutorial you should be able to get the radios working. That tutorial sure helped me. The code in the simple examples has been proven to work many many times. If it does not work for you, there is likely a hardware problem.
Run the CheckConnection.ino (look in reply #30 in the tutorial) to verify the physical wiring between the radio module and its processor (Arduino).