IMPORTANT: This Guide Is For New Players/Players Who Don't Have A Lot Of Gold. (You Can Also Use This Guide To Get Your Professions Up.
Farming and Getting Ready!
First, hit level 6 or 5 and head to the nearest main city. Then find the mining and skinning trainers learn them both and buy a Skinning Knife, And a Mining Pick. Finally buy as many 8 slot bags as you can.
Next head over to Durotar for Horde or Dun Morogh for Alliance. Spend about 30 minutes to and hour farming around the route everyday. (In the spoiler) Run the route mining all the nodes and killing all the boars, then skin them and collect Chunk of Boar Meat. Also make sure your map is fully zoomed out and you've got Find Minerals on. [Spoiler]
Sorry for Big Maps[/spoiler]
Listing Or Selling on The AH!
Ok, So when you've finished farming start head back to your main city, and vendor all your trash, then go to the AH.
Tips: When Listing Copper Ore see what sells best Copper Ore or Copper Bar.
When Listing Your items, put then on for 12 hours and under cut and competion.
You won't make that much gold form this guide if your level 80 or leveling an alt, and have gold on it already.
P.S I know it's only a short guide, but this method helped me get about 100g when I was level 8 or 9. Know that's a lot of gold to new players.