I am new to electrics myself and found all this difficult to grasp. For my F3A I used the following method.The wattage /pound to find watts. if no watts for motor use the stated ESC less 20 percent and the battery voltage you intend to use to calculate the watts. Remember that most like to fly electrics at half throttle, and so you will need to up the watts some what, say half more than calculated. Now you have the motor watts, esc, and battery and need to find the propeller.One way is to use a calculator to narrow the search, or buy a number of props, and using a good fishing scale and watt meter, find the prop that gives thrust equal to weight with the least wattage close to half throttle setting.Hope it helps, it is certainly a good starting point.