Harvesting has 4 class types. They are Foreman, Gleaner, Prospector and Reaper
More info can be found
here as far as what each class brings to harvesting.
The following FIVE material types can be harvested.
- Metals
- Minerals and Gemstones
- Textiles (cotton, etc.)
- Herbs
- Wood
A Harvester may harvest any of the 5, and is not restricted to just one type, unlike some other games. Harvesting uses its own set of stats to determine how easily you can accomplish your tasks. Just like adventuring armor, your harvesting gear will give you boosts to the stats that are only used when you are in that sphere. If you think you might want to harvest during a hunt, adventure, or raid, then you better bring along your harvester gear. All that plate mail only serves to get in the way when you are trying to swing that axe or that pick. You wouldn't wear a leather apron to fight a dragon and you won't try to chop down a huge tree wearing mail.
These points bring up some exciting issues that you will have to deal with. You won't be able to fight nearly as well in your harvester gear, so you may want to adventure/harvest in groups of 6 or 8 and alternate between half of you killing off the aggro beasts that wander by, and half of you harvesting the local bounty. Like any other game where there is a risk/reward component, the better stuff is going to be in the most dangerous places.
This was found here