Also one other thing, if you want to receive data from the master to the slave and then print that data from the slave, you need to have a ARD mega, because a regular UNO will not be able to do both.
Unless, your master has a LCD display in which case it can do both, but to get the data from a RF or BT module and then display it on a computer monitor, it can't do that.
MEGA:
Serial.begin(9600); //print the incoming data to the screenget the incoming data
Serial1.begin(9600); // get the incoming data
Serial.print(/your data here/); // NOTICE the Serial"1" this puts your data on a different TX/RX to be output to the screen.