I make my living working on peoples homes, and I get jobs every year from home owners wanting to get their places ready to sell.
In my opinion, the smart ones are the ones that have talked to a good realtor that was blunt and honest with them about their house. Homes are like fashion. Most buyers don't have a clue about quality, layout, or issues. They look at paint color, lighting, cabinets and whatever the latest trend is. The best house in the world, for the best price, is going to struggle to sell if it's painted the wrong colors. People cannot get past what they see in front of them.
When I say "good realtor" I'm referring to those that sell dozens of homes every year. The tops ones here will sell a house every week. The vast majority of realtors are lucky if they sell one a month, and some only sell a few a year. Never talk to a realtor because that person is family, a friend, or even worse, a friends relative. Find out who the top 5 or top ten sellers are in your area. They are doing something different then the others.
DO NOT HIRE ANYONE until you have talked to all of them!!!!!!
Most realtors get hired because they are nice. Nice is good, but you want smart, knowledgeable and a proven record of getting the job done.
The realtor will tell you what buyers want, and what they are not liking in a house in your area. This is very different all over the country. What sells here probably wont do as well there. Do what the realtor tells you to do, and nothing more.
My clients tend to want to spend money on things that they have always wanted to do, or what has bothered them for years. A lot of the time, it's not something that will affect the sell of the house, and they are just wasting money. You are not fixing the house for you. Whatever you do to the house is to make it more desirable to as many potential buyers as possible.
Things that I would suggest you do before selling is to declutter. The more stuff you get out of the house, the more open it will appear. Wall color has a big impact on buyers. Something neutral and uniform through out the house is the safest. White is probably the best choice for wall colors right now. Bathrooms and kitchen should have a very sanitary feel to them. Tile, grout, cabinets should all be as close to pristine as possible. I just removed 5 layers of wallpaper from a bathroom a month ago, then textured the walls and painted. It looks like a totally different bathroom. Flooring needs to be something current, clean and in good shape. Kitchen's are where you make your money, or lose it. The current trend is to paint the cabinets white. I hate it, but it's what buyers are wanting. Granite counters will sell a house faster then any other single improvement. Curb appeal, some flowers and a lawn in good shape are also important to getting top dollar.
If you can, try to walk through some new homes to see what the builders are doing. They hire people to figure out what buyers want.
Never do anything that is too trendy. Odds are that it will look great today, but be embarrassing in a couple years. Be VERY CAREFUL about letting your wife made decisions on design. They tend to be more influenced by trends, and what everyone else is doing. I can't even count how many times I've met with clients that tell me they want to remodel their kitchen or bathroom, and they want it to be the last remodel that they ever do because the last one went out of style and became dated. Just think of glass tile and how it was so popular just a few years ago. Then they tell me that they want fake marble tile, subway tile and grey paint. This is the most current trend, and the one that every wife seems to copy from every other wife.
Also keep in mind, that it's easy to spend tens of thousands of dollars on getting a house ready to sell, and not seeing any of that money in the final sales price. Your realtor will tell you if you will get more money for a remodel, or painting, or landscaping. And if you should, or should not spend that money.
