One of the most important things to gold makers is inventory. You will be dealing with two main types of inventory, your on-hand or short term inventory, and long term inventory or stockpiles.
Your on-hand inventory is what you have for day-to-day operations. The best way to manage it is using item tracking add-ons such as Altoholic or TradeSkillMaster, which count the items on your account and places it in the tooltip. When you go to purchase new materials off the Auction House these add-ons will tell you how many of each item you have and on what characters, simply by hovering over the item. Go through your dealfinding search and top up any supplies that you are low on.
Tip
Don't wait until your stock is completely depleted to buy new materials. As the market goes up and down, you may have days where you aren't able to purchase the materials you need. If you keep your supplies topped up, you can easily withstand a small drought of materials.
Once you collect the...