I've been dealing with some RL stuff the past couple days, but it's nice to log on to 20k+. It's even nicer that with TSM and Auctionator, I can be fully restocked and posted on the AH in less than an hour. Addons can mean the difference between slaving away for hours or a business that pretty much runs itself.
It's been said before, but...
TradeSkillMaster can be scary to look at when you first install it. You look at all it can do, all the groups for crafting and posting, and you just think, "where do I even start?" Take the time to set it up correctly. I myself followed Zoxy's guide. It may take up to an hour, perhaps longer, but that is an investment in your gold making business that you will not be disappointed with.
Auctionator is such a boon. I used the buy feature a lot for herbs and ore to get them all onto one page. The sell tab is amazing for items you don't have in groups and allows you to buy and post from one screen. That feature alone is worth the installation in my view.
What addons do you use for your auction house business? How do they help?