If you are just starting out in WoW, or your professions aren't that high yet, you should drop them and pick up at least one of the gathering skills, skinning, herbalism or mining. Skinning is always a great gathering skill, as many different crafting professions use leather to create goods. The same with herbalism and mining. Without the mats that these professions provide, you cannot create some of the great items you'd like to sell.
Therefore, if you are really serious about earning a TON of gold, then take up two gathering skills. This way, you know that you won't be worried about getting mats to make items, but you'll be selling all the mats you gather for gold. When you choose your gathering skills, you should not choose mining and herbalism. Both require you to use the minimap to find herbs or rocks to mine, and you can only use one at a time, so you will be defeating yourself with this combination of professions. You should always choose skinning as one of your gathering skills since you can skin other character's kills and you pretty much get to loot something twice if you kill it.
The professions are always a great way to go if you are only in it to earn the gold, after all, this is your guide to making a ton of gold, right? The only other profession that can be included in gathering is enchanting, but we'll put it in the crafting skills. The reason that enchanting can also be considered a gathering skill is that you can disenchant (DE) low-pay (green) items to get the mats needed for enchanting. You can also sell these mats on the AH or to other players for a good profit.
