You have a lot of good responses and great places to begin. I have a couple of suggestions and things to consider that weren't mentioned already. First of all, yes, the kitchen and bath are still the areas that best sell a home. However, what to put in that home depends on the area you live in. Builders and sellers are always looking for the latest and greatest in order to stay ahead of the competition. If the homes price point is in the 1st time homebuyer category, they may not be in the market for all the bells and whistles. A first time homebuyer "may "simply need/want fresh neutral paint, good clean flooring, good working air & heat systems, and a comfort that they will have time to recover from the closing before the home needs repairs. Of course, they will have request such as # of bedrooms, baths, square footage, etc. However, if you purchase a home that increases in value and ends up surpassing the first time homebuyer price point, you may be looking at more bells and whistles. In my area, granite counters and upgraded flooring are a staple for many homes. Some sellers who purchased homes 7-10 years ago are finding themselves having to upgrade their homes just to sell them. I'm sure they wish they had done this earlier so they could have enjoyed those upgrades. I suggest you build a relationship with a local Real Estate Professional who can point you in the best direction. Afterall, we're usually the ones the buyers express their needs and desires to. Most Realtors also keep a list of recommended vendors should you find a project you can't complete yourself.
Another thing to consider would be basic expectations of buyers today. I live in a high tech area so my buyers often expect homes to have ethernet cable. Even if they don't work from home, chances are they and their families are high tech and use technology daily. Builders are usually in tune to buyers needs and desires and will provide these things as part of their home purchase. You may benefit from keeping a watch on the new homes in your price range and area and borrowing ideas from the builders.
Looking ahead to resale value can be very wise. You may want to compile a list of things you plan to do so you can take advantage of sales. For example, if you plan to add a deck and the cost of wood is at its highest, you may want to complete another project first as long as the deck can wait. Check Ebay, Craigslist and other sales for items you may need to replace. You would be surprised what you can get. We've been fortunate to find a kitchen sink, garbage disposal, digital thermostats, and more online, all new for less than retail. Also check for a local builder reuse center. In Raleigh, NC, Habitat for Humanity takes in unused items from builders and the community. They sell them to fund their projects. So, you can get a good deal and help a good cause.
You've probably heard the word "green" used a lot when referring to homes these days. Is this a trend or the wave of the future? In my "opinion", we need to take notice and keep tabs because it may be here to stay. With that being said, a lot of first time homebuyers are looking for a place to live in which they can walk to do many of their errands and enjoy entertainment. The idea is that it saves money, supports a healthy lifestyle, and is good for the earth. In addition to that, they are looking for homes that use natural materials that come from renewable sources such as bamboo. You will have to do a little research with that and decide if the cost of going "green" can be recovered when you sell your home.
I truly hope all these suggestions help. Best of luck with your home purchase and updates.