Other useful addons are Cartographer, Routes, Gathermate, Xperl, and Auctioneer.
Cartographer: Exposes the entire world map and offers other features as well that I haven't explored much.
Routes and Gathermate: Both go together nicely. Gathermate, along with a Gathermate Database, gives you little icons for all the various profession nodes, such as mining and herbalism. Routes takes Gathermate data and creates a route with it for the fastest (usually) possible path to go while getting those mats.
Xperl: Just a nice portrait addon. Makes the player portraits 3D, makes the stats bar look nicer and provides health in a percentage or its literal amount. Other features it provides are telling you when you have aggro, how many things are targeting you, or how many things are targeting the thing you are targeting. Shows the target of your target, etc.
Auctioneer: Stores data on the auction house history, good for selling items at the servers economical average.
Also, what server are you on and what's your character?