One of the biggest gripe about for-sale boards is photos and price.
Photos- you're going to be taking them anyway- why make people wait and ask for them? Post them with the ad
Price- like the rules say, if you're unsure on value, either ask or Ebay. If you want every nickle for it, post high and keep reducing regularly until it sells.
Contacts- I HATE wanting to buy something and not being able to contact the person- or try for a week and find out they've been on vacation. If you're leaving, wait until you come back. Clear method of contact is a must. If you want that to be system PM, make sure your box is clear.