Addons

TradeSkillMaster - This is the MUST HAVE addon for auctioning. It is incredibly versatile. It can do pretty much anything you need with regards to auctioning. Be patient with this addon when you first start. It can be overwhelming. It has various modules for a variety of uses. Try starting with the TradeSkillMaster (core), TSM_Auctioning, and TSM_AuctionDB. These will get you started on auctioning. Once you are ready to set up shopping lists in which you can search for multiple items at once with great ease then you will want to pick up TSM_Shopping. You can even download an app to your PC that will notify you when things on your deal finding lists go up for sale with the TSM Application. How awesome is that! Be sure to check out Faid's tutorial on how to use TSM. She does a fabulous job at explaining how it works.

The Undermine Journal Addon - This is a great way to see the market averages for an item at a quick glance.

Auctioneer - Even though TSM takes over many of the functions of this addon I still find myself using it quite a bit.

My Sales - Is a good addon for keeping track of what you earn and when you spend. I am not sure if it is still being updated but it still works for me as is.

Elephant - This is a great addon in general for logging chats. It is doubly good for keeping track of sales and for copying those pesky names with special characters.          

Bagnon - This is great for making all of your bags into one uber bag. It is so much nicer than muddling around in multiple bags to find things. Please Note: I disable the Guild Bank option. I fin the original interface to be much more intuitive.