Scan first thing in the morning, while you take a shower. It will take about that long (unless you take long showers!).

Don’t rely on the recommended prices unless you see the item listed more than about 50 times. Over 100 is better.

Immediately after your scan is complete, use the search functions. The search functions only apply to the last scan, and if you wait, the actual AH auctions will change.

Scan at different times in the day for truly accurate prices, unless you will only ever be listing items at the same time every day. Prices change throughout the day with the population of the server.

ONLY scan at your faction’s auction house. The neutral AH contains completely different prices, and at the time of this printing, your data can become skewed. Not to mention that profit margins at the neutral AH is less because of the obscene cuts they take.