Instructions
Turn on your PlayStation 3. Make sure that the game tray is empty.
Select the "PlayStation Network" icon from the PlayStation 3 menu. Scroll to the "Sign Up for Playstation Network" option.
Enter your date of birth and create a sign-in ID and password when prompted. You will also have to select a security question and provide an answer.
Create an online ID. This online ID will be displayed on the PlayStation Network. Then, enter your real name and address.
Select the "Proceed to PlayStation Store" option when this appears on the screen.
Log in with your sign-in ID and password and choose the "Games" option at the top-left of the screen.
Select either the "Downloadable Games" or "Demos" option. The free games will have the word "Free" listed next to the full game or demo.