The Furbolgs of the Timbermaw Hold are located in the cave that connects Felwood, Winterspring and Moonglade. When first encountering them, they are hostile towards the player. Killing them is not recommended, though, as this will result in a lot more work required to reach exhalted reputation.
There are lots of reputation factions that you might want to increase when you first hit level 60. The Thorium Brotherhood provides some great crafting recipes for Tailors, Leatherworkers and Blacksmiths, including Fire Resistance gear, which is required for some bosses in the Molten Core and the Blackwing Lair.