Once you hit Lv30 you can buy in aven (493;439) gathering tools for 2g each. There are 3 types of tools that collect different kind of materials: Pickaxe (Mine) Crystall Ball (Altar) Gardening Gloves (Farm).
At lvl 45 you can buy expert tools that gather lvl 45 materials.


Each tool has 180 charges: once you start gathering it uses automatically 1 charge every 10 seconds. So you can AFK for 30min and when you are back you'll find the mats in your backpack.
You can stop the gathering and resume it without loosing the tool or the charges. But you can keep only 1 tool of each type in your backpack: so if there are less than 20 charges left and you have to leave, I suggest that you destroy it and buy a new one to keep in the backpack (always keep one tool so you can quickly afk and gather, even if you are in a field hunting mobs).

Since these mats are used for racial crafting (in particoular glyphs and trophy enchant) there's always a good demand: you can easily sell them in Auction House (under Related Cities you find the Farm, Mine and Altar Section).
I suggest to buy each type of tool and then try to sell the mats to see which one has the highest price and sells faster.

How to use Gathering Tools
Every time you are not in an instance (Dungeons, Territory Wars, Player Houses...) you can press G then Go to Guildtown. If you don't have a guild or your guild doesn't have a guildtown you can go in any other guildtown.

I've added to the map of Eden Glen (forest type guildtown) and Eden Peak (mountain type guildtown the icons of the tool in the corresponding site.

Once you are on the site right click on the tool and it will start gathering. If you get the error Unable to use the item. Wrong Place move around a bit and keep trying till you find the right spot; the boundaries of gathering areas aren't really clear.

To Sell the Materials
In Auction House use the search function in the correct category to select only the item you plan to sell; then check the prices of the ones already auctioned. If you are in a rush for gold (or you don't want to risk expired auctions) put the lowest price available at that moment. Though I suggest that you use the average price at that moment (stack of 50 or 100 are a good reference for that).
Stacks of materials tend to sell easier than odd quantities: so use multiple tools and then sell stacks of 100 white mats and 20-50 green mats.

Example
IWith ONE crystal ball I got 77 Magic Shine and 20 Light Effects. I checked lowest price in AH: 300s each MS and 1.5g each LE. So I would have earned 53g from the sale - 2.6g of AH fee and 2g of the gathering tool = 48.4 gold in 30min of AFK.
Note that the quantity of items gathered varies from time to time as for the prices of the mats (that are usually pretty stable though).

HTH /eth

edit:fixed grammar

hey iaaf, 1 question. I heard that we can xchange Eden Amethyst with the NPC in Aven for some sort of boxes.

What can we get from these boxes?

cant seem to find info on what comes from the 3 different box.

For those that don't know what's this about: with lvl 60 gathering tool you can collect other than regoular mats, Eden Amethists. You can exchange 1 amethist for one of the 3 types of boxes at the npc close to the ones selling the tools.

From the boxes you have a chance to get Black Hole Energy (Heirloom Magic Chest) Blue Coral Mushroom (Heirloom Herb Chest) Sunlight Diamond (Heirloom Ore Chest): you need one of each and 100g to create a siege machine through fusion in Territory Wars. In AH they are around 10g each.
Other than these yellows mats you can get random mats of various levels and grade

The particular merchant you can exchange Eden Amethyst with is called "Collecting Expert Henga" and like iaaf83 said he can be found near the NPCs that sell the gathering tools.

One more thing that you can get from these heirloom chests is alpha gathering tools for the box you pick. So for Ore chests you have a small chance to get a level 30, level 45 or level 60 alpha pickaxe and so on. These have more durability than the white ones you get from the NPCs and have a slight chance of gathering extra materials. The chance to get extra is lower than a Prime as well.

Zetsumei418 wrote:

One more thing that you can get from these heirloom chests is alpha gathering tools for the box you pick. So for Ore chests you have a small chance to get a level 30, level 45 or level 60 alpha pickaxe and so on.

Ty for reminding; I forgot about alpha tools: it may be 'cause I never got one, but then again I haven't exchanged many amethyst: I prefer to sell them and buy the TW mats whe they are 5g - 10g in AH.