The best thing you can do to keep your knives sharp and to avoid wear and tear on the blade's edge is to make sure to use it on the proper cutting surface. Using a cutting board made of glass, stone, stainless steel or ceramic will quickly dull your knife. For this reason, it's advisable to avoid using your kitchen knives to cut food directly on ceramic or porcelain dinnerware or on granite or marble countertops. The better option is using cutting boards made of wood, bamboo, plastic or synthetic because they will not dull your blades.
It's also important to keep your knives clean. Ask any professional chef how to wash a good knife and I would wager that 99 times out of 100 you will get the same answer and a stern one at that: A kitchen knife should always be washed by hand after each use using a mild liquid detergent And then treated thoroughly with a towel. And then that same chef will tell you, and with great emphasis, that a good knife should NEVER be washed in a dishwasher because the heat and steam will ruin wood handles and the knife can be easily nicked by being tossed around in the dishwasher.
All this being said, I have to admit (and I realize that I may be about to incur the disdain of many amazing chefs by doing so), that I sometimes wash my knives in the dishwasher, because, due to safety reasons, I don 'T like handling a sharp blade with wet hands. For this reason, I only buy plastic-or composite-handled knives because wooden handled knives really should not go into the dishwasher. And I've never had a problem with my knives getting nailed in there, although I'm very careful about how I load them.
If you choose to wash your knives in the dishwasher, make sure to place them securely in the top shelf of your dishwasher so that they will not move around during the washing cycle and do not use the heated dry cycle. For safety sake, be careful unloading the dishwasher. And, remove the knives from the dishwasher immediately after the washing cycle is complete.
In addition to keeping your knives clean, it's a good idea to keep them sharpened and in alignment. A honing steel is an essential piece of equipment if you want to keep your knives in tip-top shape. The honing steel is not a sharpener, but is used to re-align and straighten the blade's edge. By pulling the knife's edge along the length of the honing steel, the blade can be brought back to the correct angle. Manufacturers recommend using a honing steel every time you work with your knives.
As far as sharpening your knives, there are a number of home knife sharpeners on the market today and many of them do a good job at returning a reasonably sharp edge to your blades. The manual sharpeners are significantly less expensive than their electric counterparts, but just do not seem to be able to manage a blade that is pretty dull. If you keep up with your knives and the blades are only modestly dull, the manual knife sharpener is probably fine for you. Otherwise, you'll probably want to invest in an electric sharpener. When shopping for an electric knife sharpener, you may want to consider getting one that includes a non-motorized slot that can be used like a honing steel. This will save you having to buy the steel in addition to the sharpener. In addition, the honoring mechanism on the electric sharpeners is much easier to use than the traditional honing steel.
The other option for sharpening your knives is to take them to a professional knife sharpener. This choice is certainly less convenient than running the blade through a sharpener at home, but nothing can give your blades a sharper edge than an experienced professional can. In fact, many professional chefs say that having your knives sharpened by a professional knife sharpener is the only way to go.
If you're interested, most good kitchenware shops can direct you to a qualified person. Or, you can also look under 'Sharpening Services' in your local Yellow Pages.