How to Join Online Play With PS3

Connect your PS3 to the Internet. You can connect through a wireless or wired connection.

Register on the PlayStation Network using either your PS3 or a separate computer. On the PS3, navigate to the "PlayStation Network" menu and select "Sign Up for PlayStation Network." You will then follow the prompts to create a new account, entering personal information such as a username, password and email account.
If using a computer, go to the PlayStation Network website. Click ̶0;Join Now̶1; and create your profile.

Scroll to the far right menu settings to find the PlayStation Network sign-in if you are not logged in automatically . Enter the PSN username and password you chose during registration.

Insert the game you wish to play online. Keep in mind that while most games now have some sort of online or multiplayer option, not all do. Be sure to read the back of the game box before purchasing to make sure the game is capable of online play.

Scroll through the game's menu and find the ̶0;Online̶1; or ̶0;Multiplayer̶1; option. As long as your Internet connection is working and you have logged onto the PlayStation Network through your PS3, you should be able to join online play.