The best thing you can do for a good knife is to keep it sharp, and the best way to sharpen it is to use a whetstone or water stone. This video contains a simple, quick walkthrough of how to do it at home.
We've shown you how to keep knives sharp before, and we even discussed why water stones are best, but this crash course is quick, fast and gets to the point. The most we can usually do at home can do is either hone our blades with a honing steel, which straightens and lines up the blade's edge, but it doesn't sharpen it. Alternatively, you could run it through a handheld or electronic sharpener, but sometimes you can do more harm than good.
A good whetstone will keep all of your knives sharp and in perfect condition. The beauty is that it doesn't take much effort to learn -- just practice to get the angle right and keep a consistent angle while you're sharpening. Whetstones are available in department stores or online, and while they range in price based on the fineness of the grit, this thread at eGullet can help you pick the right one.