Adventures with needle and thread.
Tailors produce goods primarily for scouts and mages, as the bulk of what they make is cloth and leather armor. Bags are often their top money-makers as well, because people who are leveling up always need larger bags to hold all their loot and equipment. They can also produce quivers - useful for classes that use ranged weapons. They're also the only artisan class that can produce cloaks, which are useful for every class. That makes tailor a relatively well rounded equipment production class, as they have a main focus on producing light armor but they can also make items that everyone wants.
Tailors can also produce fancy clothing just for fun. You might be surprised at how much some people will pay for an item that just looks cool - experiment and see what you can get for some of your attractive items. Roleplayers in particular like to dress up their character in colorful ways. Check prices on the broker if you're not sure as to how much you should sell your items for. The more that you learn about what other tailors charge, the better chance that you'll have to sell your items for the most that you possibly can. Tailors use lots of root nodes along with some ore, animal pelts and wood. They don't really need to harvest food, soft metal or gems, but you can still grab it to sell your extra on the broker. While tailoring isn't as expensive as armorer or weaponsmith to level up, you still need a lot of expensive materials to get better at it. Sometimes it helps to save up some money before throwing yourself into tailoring full on.
While you're leveling, it's best to use tradeskill work orders to defray your costs, get some additional experience and benefit your guild. This also prevents you from flooding the broker with low level items, which in turn helps other tailors to sell their goods at a higher price than they would be able to otherwise. If you're trying to make the best items possible, it's best to use imbues and adornments, although both systems are a little complicated for a new player to understand. Rare hex dolls that tailors can craft often have significant statistical buffs, and sell for excellent coin. Those are often one of the tailor's highest selling items, as they can be used by any class and have many excellent benefits. Some can also cast strong debuffs or buffs, making them even more useful.