Here's the fact of the matter: nothing is going to automatically make gold for you in Warcraft.
WoW's economy has been extremely stable considering how long the game has been in play. There has been some natural inflation in WoW gold, but this is to be expected to a degree as the years go by and the obtaining of gold becomes easier in general. But the fact that the economy is stable shows that there is no "get rich quick schemes" out there (in real life or in WoW!). If there were then everyone would have abused such schemes long ago and the economy would have been trashed. However, that being said, you can take heart in the fact that WoW's economy is not so different from the real world in numerous ways.
1) You have to spend your personal time working in-game to provide something to players that they themselves can't do (whether because of lack of time or lack of brain power). In other words, you have to provide a service of some sort. So take up a gathering profession such as herbalism or mining and then simply sell what you gather on the auction house. This is the quickest and surest way to make gold in my experience.
2) Become very familiar with the auction house. If you blithely put resources up at the auction house without regards to the bid and buyout then you'll likely be undercut by other players frequently and will miss out on a lot of gold. This also means understanding when prices will be the highest or lowest for a resource (ie - the weekends usually affect prices one way or another because that is when more players are on).
3) Take up a crafting profession and sell what you craft. The trick here is to find your niche in the AH. It requires finding something that you can craft that will sell for an amount of gold that justifies the time it required you to make the item. An unfortunate drawback to this tactic is that it often requires probing of the AH to determine what sells and what doesn't. By "probing" I mean it requires you to make the best guess you can at what might sell, crafting it and then putting it up at the AH. There is more risk to this method (as you may craft something that just isn't in demand and will sit on the AH for 2 weeks straight), but inversely there are more gains to be made should you find your niche.
4) Daily quests are an excellent way to make gold also, with the additional chance to find resources (ore, herbs, skinning, BoE items to disenchant) while you're doing them.
Lastly, I can't reiterate the point enough - you have to be willing to spend time doing something to make gold. It's just like real life. You have to find your niche, whether it be in the auction house or whatever, and then use it to make gold. It's as simple as that, if such a thing can be called simple.