Professions are the best way to make money on World of Warcraft, but few people really master how to make money from them. Most people work hard to buy all the new patterns, gather tons of materials, and spend all their savings on training in their professions... only to take a net loss of money in the end. The key to making money is being selective with how you do your professions. I used to take in over a hundred gold almost every single day, mostly without even having to leave the major cities. It took a lot of money and a lot of hard work to get to that place. The key is where to start.
Mining, Skinning, and Herbalism are gathering professions. They are primarily used to pick up materials for use in the other production professions. Not everyone has the time or cares enough to gather their own materials, so they just buy them on the auction house. This is where you come in. The best way to make money is to pick two gathering professions and just pick up what you see in your travels. It's best to get either Mining OR Herbalism AND Skinning. If you get Mining and Herbalism at the same time, you can only track one on your radar. You will have to either constantly switch which you want to track, or just look for them with your naked eye (which is usually quite hard to do). Then just play the game as you normally would, picking up whatever you find on your travels. When you get back to a major city, check the auction house for the materials you have gathered, and set the buyout for just below the other auctions. If prices aren't very good for that day, bank them and sell them tomorrow. The auction house economy fluctuates like the stock market. Usually raw materials sell fast and tend to be quite profitable. Once you get the hang of it, you can make all the money you need.
I just started playing on a new server. I have played for about 2 hours total and I have made over 2g on my lv 6 shaman. I once made a new character on a friend's server to see how much I could make in a week. I made over 25g without leveling past 10. If you learn to play the auction house well, you won't ever need to worry about money, and you can buy all the items to boost your power and make you level faster. I have a lot of other secrets to making money, but this one is the most important for beginners. Be sure to keep an eye out for more tips from an old pro.
Every man dies, but few truly live. Live your life to its fullest, every day as if it were your last.