Fishers relax and feed themselves by catching the bounty of Azeroth's lakes and seas. Careful bait selection and patience can result in some truly rewarding hauls, from seafaring delicacies that restore heroes' health or enhance their attributes to waterlogged flotsam like cases and trunks. Fishing can even yield rare reagents and items lost at the bottom of the ocean or swallowed up by sea creatures!
Fishing is a secondary profession - anyone can learn to fish, no matter how many other professions they've devoted themselves to.
All fishing must be done in a body of water with a fishing rod, which can be purchased from any fishing trainer. Fishing in different locations (or, optionally, with different types of bait, also bought from trainers) may produce different results.
Though most of your catches will be valuable the moment you haul them out of the water, cooking is a convenient way to get even more mileage out of the fish that you catch - when they're specially prepared, many fish offer additional restorative benefits.
Stand near a body of water with your fishing pole equipped.
Face the water, and use the 'fishing' skill in your professions menu.
You'll see a bobber appear in the water, attached to your fishing line. Watch it - when it splashes, right click the bobber to reel in your fish.