Okay, I am not talking getting rich at level 5 here. I am talking about making enough money to train all of your professions and get all your new skills when you level up while not having to worry about not having enough. Sure, you can extend it and do it more, but this is just enough to get you rolling on a new server with no more then 30 minutes of your time invested.
As soon as you pick up fishing you can make enough money to get rolling. Go to the docks in Auberdine and walk up and down the docks looking for fishing pools. The docks are the perfect place to fish for a lowbie. No creatures sneaking up on you while you try to fish and lots of quickly respawning pools to fish from.
Take all the oily blackmouth you get and list them on auction (check listings to see what price to sell for). Hopefully you will end up with a few trunks as well. Open them up and sell the bolts of cloth, the leather and whatever goodies they give you on auction as well. In about 30 minutes you should easily have enough stuff that you can make 8-20 gold, depending on the server.
Whenever you are in a city check the trade chat. Anyone that says they are paying for guild sigs, sign up and take their gold. If they are willing to give it out then you should be glad that you are able to assist them in taking it from them. Again, without any time spent, just passing through a major city and sending a whisper, you made some more gold.
A few of those with your 30 minute fishing trip and keeping a hold to any white item you get to try and sell on auction, you can easily have at least 20 gold, if not 50, by the time you are level 10. All greens that you do not need (and are not spellbound) should always be auctioned off. Check your local market and look for items of the same item level. On many servers you can get 1 gold each for level 8 green items. Enchanters with lots of money and no free time are always buying from the auction market to disenchant. From here on, quest as normal and sell everything that you can and you will never have to worry about money for training again.
Now you will not be rich but you sure as hell will not be saying "I wish I had enough" when you hit level 20 and it is time to buy your mount. That alone makes playing that much more fun.