TO play online on ps3, you'll need these stuff: ps3, controller, ethernet cord ( u might have one on your computer ) wireless router ( if your ethernet cord is long enough to get to your computer, you have to buy that which might cost about well a $100.) If u dont want the router but u have a modem of ethernet connection somewhere on your computer hardrive, the only thing that might be difficult is you have to move your computer somewhere near a tv with your ethernet connected to the ps3.
Games that can be played online can be useful if u have internet connection which u are playing all over the world!
Easy way: if u have a labtop, it might be easier cause it portable and you can still play online if u have ethernet connection.
If u have any questions: Email Id removed for security,
or call customer support which I have no idea what is the phone number.
Other to get help: go to where ps3 are bought like target or best buy.
if you are done and you have the things to play online, Start playing and enjoy! :) :D