I used Robin2's simple rf24 tutorial to get my radios to work.
The rf24 radios need more current than most of the 3.3V regulators on Arduinos can supply. A 10uF (min) cap across the radio power terminals close to the module will sometimes help. There are adapters available with a separate regulator.
The high power radios may not work if too close together. Separate them by a few meters.