What should I do to prepare for a home appraisal?
You may want to prepare a list of any recent improvements, description and/or receipts for major maintenance replacements & ages (AC/Roof/Water Heater/Appliances), and any information you have about recent renovations. You should also do your best to make sure the home is clean and clutter free.
Cleaning - Appraisers are accustomed to seeing properties in all types of condition and an experienced appraiser will have been inside thousands of homes. Sometimes people obsess over cleaning, but it really is not necessary to go overboard. As long as the home is not filthy, it is not going to make a huge difference on the appraiser's impression. They are looking at the materials, upgrades, quality, paint finishes, flooring, landscape, roof, etc. as opposed to how much dust is on a shelf.
Photos - Every room is usually going to be photographed. If you will be embarrassed by having laundry laying around or dirty dishes on the table, you should put them away prior to the appointment.
Clutter - You probably have been obsessive about having a de-cluttered house while showing the home to prospective buyers, but appraisers are accustomed to seeing homes with occupants that are in the middle of a move. You don't need to stress about light clutter, but you should try to clear off any major components such as appliances (at least enough so that they can be tested), provide clear access to doorways, and try to have enough clear space for decent photos in each room.
Documentation - Typical residential appraisal forms require the appraiser to estimate the time period of various renovations specific to the kitchen and bathrooms. If you know when the kitchen or baths were last renovated, consider writing down some notes for the appraiser. This also applies to other major renovations (flooring, fixtures, lighting, etc) and maintenance items (roof, water heater, AC, etc). Try to provide any association or property management contact information, general community information, or special mandatory association requirements if they are known to you. A copy of a survey is also always appreciated.
By Owner Sales - Any information about advertising that you did for the sale (web site page prints, classified ad dates & information, etc) is helpful. The appraiser will want to understand the time on market and document the history of how the contract came about if possible. For this reason, it can be helpful to provide information like the original asking price, the approximate date that you first made the home available to purchase, and the way that you found the buyer (open house, word of mouth from a neighbor, etc). You also may want to have a copy of the contract and any addendums available.