Kitchen knives have to be sharp. Honing with whetstones of different grit gives the best results.
To keep your knives sharp, you can take them to a shop, or learn to sharpen knives yourself. There are excellent sharpening shops that work with wood-cutting and surgical instruments, with all kind of equipment you don't need at home and staffed by people who like a good blade. In a typical shop on a farmers market they'd just grind the blade on a belt or rotating stone and touch it with a steel if they felt like being extra nice. It pains me to see it -- the guy returning the ruined chef's knife to a happy housewife and charging her $5-$10 while the sun shines on the edge.
Everyone who has something to say about knife sharpening seems to have a grandfather who really knew how to do it. My grandpa had a huge electrical motor with grinding stone on it. It was an exciting contraption: it made noise, it smelt, it got hot and made sparkles. It sharpened crappy stainless-steel knives we had then in seconds. I doubt it could be useful for a better blade: the heat, for one, destroys the temper of the blade. The rough grit grinding stone can be used to strip away the damaged edge. It will leave fine sawtooth like scratches across the blade. After that, the restored blade needs honing. In America and Europe, the only people who care about sharpening their instruments are woodcutters. European cooks grind their soft stainless-steel knives on electric knife sharpener and fix the minor dents and splinters with a steel. Japanese cooks hone their knives on whetstones. It takes time and patience to learn how to do it, and it is a long process -- but a good knife holds an edge for a long time.
The usual test for sharpness is shaving the hair on the back of one's hand. Some people try the edge with their thumb or with the thumbnail. Yet another test is to hold the knife with the edge towards you against the bright light: the sharp edge wouldn't reflect the light, but the dull blade or dents would. Once you decide your knife needs honing, you need a stone.
Sharpening stones are small crystals of quartz or aluminum oxide (as in sapphire) held together by softer mineral, like clay. There used to be several different minerals in different parts of the world used to produce oil- or water-stones. Now the natural sources are mostly exhausted. Synthetic blade sharpeners now are made of quartz, aluminum oxide or diamond binded in clay, or polymer resin, or vitrified. They have predictable grit. Oil-stones (Arkansas stone, India stone) have to be immersed in kerosene/mineral oil mix. Water-stones, like the whetstones sold by Global for their knives, have to be immersed in water, or splashed with it for fine-grit ceramic stone, and kept away from oil in any form. Water-stones are better than oil-stones.
The grit corresponds to the size of abrasive particles. The larger the number, the finer the grit. It's best to start with medium stones. The abrasives vary in hardness (quartz is 6.5, aluminum oxide 9.2, diamond 10), but every one available is harder than the hardest molybdenum-wolfram steel used for kitchen knives. Global two-sided water stone, rough/medium (brown/blue, 240/1000 grit) costs under $70. It comes with a handy resin base and an excellent instruction. Start with it, learn how to maintain the consistent angle to the stone, and get the finer stone once you are confident. Use rough side with great caution and only to repair damaged blades. Make sure your knife is absolutely clean. Protect your working surface -- the dissolving resin will stain. Keep the stone wet. After use, wash everything in an empty sink and make sure steel and abrasive particles don't get into dishes. I have a Pyrex glass rectangular container to keep and water the stone. The important part is the same container never used for anything else. Super ceramic whetstone (pink, 5000 grit) costs about $85. These stones sold under slightly different names -- whetstones or water stones, double or two-sided, etc. The grit and the color are the same. Global also sells ceramic rods ($95) and small Mino-sharp water sharpener with rough and medium wheels ($30 or so) that is handy and doesn't take any skill to use, but will not replace careful honing. I have one, as well as above mentioned stones. Sharpening guides are used to maintain the same angle. I never used one.
See also: kitchen, kitchen knives, stand mixer, coffee grinder.