How to play online on Minecraft with the ps3?

You simply download it from the PS Network, head over to the multiplier section in the game and add a server to the list.

Download it, then before selecting a world, if any friends are playing it, thre name will be there so just click join

You need to have friends playing the game and invite them or have them invite you.
If you need someone to play with my PSN is nvrmisundrstood
You can usually find lots of people to play with