You have 2 panes to open up to the right side,
“Item settings” which lets you choose the pricing strategy to use, highly recommend to play with this as some of them, especially “StackAware” is handy for selling mats in bulk (it undercuts price of lowest item that has at least 80% of the stack size you want to sell), so it will bypass items posted with stack size of 1.
“Auction Info” which has details like Per Auction price, and deposit fee. You can also view historical price charts.
Also when buying be sure to tick “Fast Mode”, however if you spam buy too fast, you will see some errors, but its still ultra faster than other AH addons when buying and selling.
Full Interface looks like this: