I've been playing World of Warcraft for over two years, so I know that the biggest frustration players have is figuring out how to make enough gold. Without enough gold, you can't purchase repairs, pots, new armor/weapons from the Auction House, etc.
Many players are tempted to buy their gold, however that is against the World of Warcraft EULA, and if you get caught your account will get banned by Blizzard.
So if you need gold but can't buy gold, how do you make gold in World of Warcraft? Here are my top gold making tips:

1. Don't buy needless upgrades. You can make a lot of gold if you save what you earn. I can't tell you how many times I've seen players spend a ton of coin on a new weapon from the AH, only to get an even better weapon a day later through questing. Save your gold and earn upgrades through quests, instances, and raiding.

2. Upgrade your bags to get more slots. Loot everything off the corpses and the sell it all. With the release of Burning Crusades, some gray items sell for several gold a piece! Don't lose focus from earning gold. If you're busy questing, your bag gets full, but you can get distracted because you're just a couple more bubbles away from leveling. Think long term. Go back to the nearest vendor and clear out your bags to earn that precious gold. You'll get back to leveling soon enough.

3. Learn the "real" money making professions. Did you know you can sell herbs for a higher profit than you can sell the pots you make with those same herbs? Crazy but it's true. Mining, skinning, and herbalism make insane profits if you focus on them and skill them up to their max levels. Install and use mods. You simply cannot make serious gold in World of Warcraft unless you install key mods to assist you. For instance, you won't know the fair market value of any item in the game unless you run the Auctioneer mod. If you have a gathering profession, the Gatherer mod will remember all the spawn points.

4. Install and use mods. You simply cannot make serious gold in World of Warcraft unless you install key mods to assist you. For instance, you won't know the fair market value of any item in the game unless you run the Auctioneer mod. If you have a gathering profession, the Gatherer mod will remember all the spawn points.

5. Learn the secret money making areas. There are certain areas of the game where you can earn crazy gold. For example, before Burning Crusades was released, you could earn serious gold by farming at Tyr's Hand in Eastern Plaguelands. If you were a skinner, you could farm Thick Leather by killing Yetis in Winterspring. With the release of Burning Crusades, there are new secret areas that make more gold than ever before.