PvP quests open up in Southshore. The Power of Pine and Crashing the Wickerman Festival are given by Sergeant Hartman in Southshore. The Power of Pine is real easy with the help of Runescape Gold, find the Stink Bombs and use the cleaner on them for a Pumpkin Treat. Crashing the Wickerman Festival just requires you to walk west of the Undercity and spot the giant wickerman.
The Horde has the quests Rotten Eggs and Stinking up Southshore. Rotten Eggs require you to place a batch of Rotten Eggs inside of the main brew keg in the Southshore inn. Stinking up Southshore requires you to use 3 Stink Bomb Clusters inside of the center of Southshore. Both quests also reward treats.