Foraging
Foraging is a survival skill used to find certain items which may be used in alchemy, fletching, or any number of other pursuits. Healing herbs are debatably the most important of the foraged items, but with enough foraging, one can find wax for candlemaking, wood for fletching, firewood, tea leaves, coffee beans, alchemical catalysts, grass or vines for braiding rope, branches for staff carving, or even items that can be used as improvised weapons, such as rocks and logs.
Training Foraging
Foraging can be a frustrating skill to train. Currently, the best methods are fishing, which works quite well until a character has about 150 ranks, or, if the character is survival primary or secondary, they can FORAGE CAREFUL for faster learning. Ideally, you want an item that takes 15 seconds to forage and can be reliably found.
As with most skills, you want to go after the most difficult item you can reliably find. A good place to start is the Foraging Compendium, which can be used by referencing your foraging and Perception skill and finding where on the chart you are likely to learn.