Gathering Professions

I'm sure most people have worked this out, but one of the easiest way of making gold at low levels is to take up either skinning, mining or herbalism. I usually do skinning and mining. Skinning doesn't make a lot per item gathered, but there are plenty of animals to skin as you level up. Light leather which can be gathered in abundance at very low levels sells for around 50 silver a stack on most servers.

Copper, Tin and Iron sell for a lot more but you will need to travel further to gather supplies. For mining, you can smelt the ores into metal bars and sell them in the AH. Check the prices in the AH before you smelt as sometimes the ore can sell for more than the bars. Once you get to higher levels, you will be gathering Thorium and Truesilver which will sell for 5 gold a stack or so.

Herbalism at high levels of skill can be lucrative but it's a little less rewarding at low levels.