I used Robin2's simple rf24 tutorial to get my radios to work. If you carefully read and follow the tutorial you should have success. if you still have trouble run the CheckConnection.ino (look in reply #30) to verify wiring between the radio module and its processor (Arduino).
If you cannot get them to work, you are doing something wrong or the modules are bad.
The rf24 radios are not WiFi and will not show in a WiFi scanner.
There is no way to test a single radio that I know of and I have been using them for at least 5 years. Get 2 Arduinos and 2 rf24 modules.
Some other suggestions:
Make sure the rf24 power supply can provide enough current. This is especially true for the high power (ecternal antenna) modules. I use homemade adapters like these. They are powered by 5V and have a 3.3V regulator on the board.
If using the high powered radios make sure to separate them by a few meters. They may not work too close together.
Reset the radios by cycling power to them after uploading new code. I have found that to help. They do not reset with the Arduino.
Switch to 1MB data rate to catch the not so cloned clones.
radio.setDataRate( RF24_1MBPS );