Basically, the only function needed from Auctioneer Advanced is the scan function. There are two packages you can get of Auctioneer so depending on which one depends on how you scan. With one package you can get a large button at the botton of the opening Auction House screen saying scan. The second is a little serise of Play, Stop, and Pause buttons at the top. Just hit the play button to start scanning, if the AH is accidently closed for some reason the scan will be paused and can be resumed so don't panic.
Another little thing that auctioneer does is to show stats of an item when you mouse roll over it. Amoungst all the crap in this little tool-tip will be the main information of: Product Name, how much per item, how much for the complete stack that you have, how many you can stack the item by, what the item is used for, and if it is used in any quests (although I generally ignor this part unless I know of a specific quest that I can use it in). This information will help you to deem the item sellable or not. Throough leveling with any character, my general rule is sell anything worth a gold or more, by now-a-days on Pala I only sell blue quality items of 10g+ and all cloth plus things for rep or which I know sell well.
Appraiser I don't really know much about since it is new to me from when I got this package so I shall have a look next time I stop by a AH. May be today I think as my bags are 50/80 mostly with crap to sell. xD
BtmScan (or Botton Scanner) is basically a little function of auctioneer which you can use while the programme is scanning the auction house. Basically it will scan throught he auction house and tell you about any item within the auction house that it thinks could be bought on and sold for a profit. This is good for those times when you can't really be bothered to go out and farm for money, but is trickey to get right as the auction house is constantly changing and updating. I have made upwards of 200 gold a day using this but have also had bad days where I have lost hundreds of gold, so only really use this function when you have some money in the kitty.
Hope this has helped a bit. If there is anything else you would like ot know juse ask me on here or get me in game. I'm the ones with 'ftw' at the end of all my character names