Once you get to level 45, you can start getting quests in Elani (Deadbog rift) which can start you earning some faction.
First, you need to choose which armor type you wish to go for. This is determined by faction.
Gorgalok Faction: Provides high offensive stats, kill in Ichtakhta.
Flordiel Faction: Provides a balanced set, kill Gorgaloks in Vsurog Moor.
Ichtakhta Faction: Provides high defensice stats, kill in Flordiel.
For a good write up, including tables with links to the armor, go here:
Ten Ton Hammer - Swamp Armor Overview
easiet way to get faction is to do the Atonement quest offered by the 3 emissaries. This quest is completed by spawning King Mnalus in Mnalus Caves (Swamps of Rumug). You have to have 2001 faction in order to do these armor sets. This means True Faction. When you kill something and see your faction go up or down, it has 2 numbers (such as -2(-604) ). This isnt your true faction however. You need to make a hotkey with the command /showfaction "InsertYouFactionHere" in order to see your True Faction.
The above website has alot of fantastic information in tables such as what is needed to complete each piece, and where it all drops.