In Lord of the Rings Online, PvP takes place as Monster Play in the Ettenmoors. This is a zone for only those who are level 40+ and you have to capture five different keeps to win. Each keep is guarded by a monster boss, and both players and monsters fight for control over these keeps. If your side gains control over these keeps, you post your NPC's, guards, and more to help you, and you'll see this change as you takeover that keep and the NPC's automatically change over to your side. You will also notice that the map will change over on that particular keep as well, so you can see where you need to go next to keep your streak going.
Now, in this area, you will also find quests and other monsters who will give you Destiny Points instead of experience when you complete a quest or kill the monsters. You will also find many great higher end resources here to make you want to head to the Ettenmoors.