Making hot dogs out of giant insects.
Cooking is a secondary tradeskill that any serious WoW player should have capped out on at least one character in their account. The buffs that good food provides are indispensable, often equivalent to a minor gear upgrade. Although there are no cooking recipes that are bind on pickup - meaning you could conceivably just buy all the food you need and never worry about raising it yourself. Most foods are relatively cheap, but the short durations of their buffs and the fact that they don’t persist with death means that most classes will end up consuming lots of it. It’s much more convenient just to be able to create the food yourself, as it’s easy to get the raw materials for most foods and to put them together.
Unfortunately, cooking doesn’t really feed into any of the other primary professions. There are many quests to get new food recipes, including daily quests only available at 70 that bestow six recipes that you can’t get anywhere else. As you will most likely level up far faster than you will need to use many of the lower level cooking recipes, you shouldn’t worry too much about collecting them all as you level up. Lower level food becomes obsolete quite rapidly as you level. Fishing helps to level up cooking much faster, although getting that to the top can be very time consuming.
Getting to Artisan cooking (to get above 225 skill) requires that you complete a quest for Zamja in Ogrimmar or Daryl Riknussun in Ironforge to collect Giant Eggs, Zesty Clam Meat and Alterac Swiss. As long as you keep up with your cooking skill, you will only rarely need to purchase store bought food. This keeps your costs down significantly as you level, making it so that you can buy your mount faster and stay more up to date on your equipment.
As of the Burning Crusade expansion, there are many great foods that you can make. Ravager Dogs take highly common ravager meat and turn them into a food that gives a buff of +40 attack power and +20 spirit for 30 minutes. Roasted Clefthoof gives your character 20 strength and spirit for 30 minutes. Cooking is particularly useful if you have skinning as a profession, as you’ll be killing lots of animals that drop meat in any case - you might as well be able to turn that meat into edible items rather than to just let it rot in your inventory.