Herbalism is an almost necessary requirement for Alchemy. You're going to find herbs all around the world, so why not get this skill and take advantage of it? Alchemy is a great skill that allows you to generate all sorts of instant and temporary potions to improve a character's effectiveness.

Getting Started

First of all make your way to the nearest herbalism trainer. Often, alchemists are situated nearby herbalists, so you can learn both closely related skills in the same location.

Finding Plants

Once you've acquired the basics, you're ready to go. Herbalism requires no additional items to use. Be sure to keep a lot of empty bag space for all the herbs you're about to pick up. If you get a lot of extra herbs that you can't use, you can store them in the bank or sell them to other players.
After you have learned the beginning-level herbalism, you will gain the "Find Herbs" ability, which will display nearby herbs as yellow dots on your mini-map. To use it, simply drag the icon down to your action bar and press the corresponding button. Be sure to pay attention to keeping it active; otherwise you may miss important plants!

If while adventuring you spot a yellow dot on your mini map, you've found a plant! Move your cursor over to your mini-map and hold it over the dot. A small window will appear and display the name of the plant. If you decide you want to harvest it, begin running toward it. Watch out for any monsters in your path that may attack you.

Plants can be found underwater and even in caves.

Getting the Goods

Approach the plant. Once you're close enough, the action cursor will light up and you can begin harvesting. If you fail on your first attempt, try again. All plants have a minimum skill requirement before you can attempt to harvest them. If your skill is too low, you won't be able to collect the herbs. Once you're successful, a window displaying the contents of the plant will open. Each plant usually contains one to three herbs. Right-click the herbs in this window to move them to your backpack. After you collect the herbs, the plant disappears.

Plant Skill Levels

Each plant requires a minimum skill in herbalism to harvest. Depending on the level of the plant, you may gain skill levels when you succeed in gathering. The further away your skill is from the level of the plant, the less likely you are to receive a skill increase. The skill required to successfully use a plant also corresponds to the regions it can be found in. Easier plants are found in the lower-level areas, and more difficult plants in the higher-level zones.