WoW World of Warcraft Engineering
Engineering is said to be the profession that all classes should use. With it you can create different machines and gadgets that you can use both outside and in combat. Example items are different bombs, mechanical squirrel, land mines, explosive sheep etc. Engineering requires stone and various types of metal so the Mining profession will be needed unless you want to buy all the materials from other players. Read Skryer' forum to get plenty of Engineering guides and more.
The items created by Engineering will not sell well to other players because almost every item requires your character to have a certain level of the Engineering skill itself. However, many of the items you create will help you and others well in combat.