The first thing you must do is obtain the aircraft operating information for your aircraft. This is usually found in the Weight and Balance (W&B) section of the POH. Note: The information in this example is NOT for actual use.
Once you have this information you need to configure the stations. The example below is a sample for a SR22. I have added the stations Empty Weight, Fuel, Pilot, Co-Pilot, Right Rear Passenger, and Left Rear Passenger.
Enter the weight and the Arm for each station. You can click the Add button to save the existing entry and add a new one.
Once you have configured all of the stations, you will see the Center of Gravity (COG) and total weight for the aircraft.
Find the Center of Gravity Envelope in the book and you will be able to quickly see where you are in the graph and make sure you are within limits.
http://www.pspda.com/blog/pse6b_weight_and_balance.html