In summary: Peter Nowlan is a professional knife sharpener based in Halifax (Canada) and he recommends the KnifePlanet Sharpening Stone Set, a beginners and intermediate kit that includes 4 sharpening grits: 400/1000, 3000/8000, a bamboo base and the KnifePlanet Flattening Stone. The Japanese Naniwa 3-stone combination is also a great (and more expensive) choice, ideal for professionals and more advanced sharpeners: the Naniwa stones are slightly bigger compared to KnifePlanet’s. In both cases, a coarse, medium and fine grit combination is very effective to sharpen and refine the edge:
You will also need at least one finer stone. Once the shape of an edge is established, successively finer grits are used to refine the edge improving the quality of the cut it delivers. A dull edge will not cut well and should be shaped with a coarse stone. An edge sharpened on a coarse stone will cut better than a dull one, but still won’t be ideal and should be improved with a finer stone. As you progress through finer stones, the cutting edge will continue to improve. How many and how fine these stones need to be varies depending on how fine an edge you require.
Once the burr is removed, it's time to test the sharpness with paper. Hold a piece of newspaper at about 45°, with a bit of tension, and slash lightly with each point of the blade. If it cuts through easily, your knife's sharp. Warner speedily lacerated his newspaper, but I of course struggled. There is an element of technique involved, he reassured me. 
A: That depends almost entirely on how often you use them. If you are a professional chef who uses his or her knives every day then you should hone them every time you use your knives. But honing has its limits and over time your edge is going to become dull no matter what. Therefore your knives will need to be sharpened at least several times a year. Some chefs, in fact, will use a whetstone on an almost daily basis in order to ensure their knives are always razor sharp. Most of us, however, are not professional chefs and may not even touch our kitchen knives for days at a time. In that case, it’s probably a good idea to hone the edge after every couple of uses and have your knives sharpened once a year.
Let’s start with Arkansas. If you have heard about Arkansas oilstone, it uses the Novaculite stone that mined in Arkansas. The most expensive of Arkansas stone is the Hard Translucent model that begins to rare in the market. If you want to shop for Arkansas, they are available in different grade starting from Soft Arkansas, Hard Arkansas, Hard Black Arkansas and Hard Translucent Arkansas. The finest grade of Arkansas can shape such of mirror polishing edges.

The toughest angle to master is the angle at which you'll sharpen the edge of the knife. For a Japanese knife, that should be around 12-15 degrees. Before you reach for the protractor, a good test is to get roughly half an index finger's gap between the spine of the knife and the stone (see above). Remember to remove your finger before you start sharpening. For a Western-style knife, you want an angle of about 20°, so raise it ever-so-slightly higher.
A: We’re all told that a sharp knife is safer than a dull knife yet most everyone knows that merely touching a sharp knife can often result in a painful cut while we can wrap our hand around a dull blade with little worry. So why would anyone in their right mind claim that a sharp one is safer than a dull one? To a certain extent it’s a matter of semantics for sure, because there is no denying you have to be extremely careful around really sharp knives. But at the same time there is a very good reason to consider a dull knife to be more of a safety hazard than a sharp knife.
Choose the style of stone. You'll need to choose a natural or synthetic stone that can be used wet (soaked in water), with oil, or dry. There are also diamond stones that are actually very small diamonds attached to a metal surface. Stones that are soaked in water are softer stones which means you can quickly sharpen your knives. Unfortunately, these stones will wear down faster than the others. Oil stones are the least expensive and they're made of a harder material.[2]
Ye olde tomato test - After you have sharpened using one of the above sharpeners grab a firm tomato and try to slice it. If the blade is properly sharpened it will slice through the skin with virtually no effort and without pushing the skin inward first. If the skin is able to fight back against the blade then your knives are not properly sharpened yet.
Once sufficiently wet, it's time to position the stone on something solid, so it doesn't move about during sharpening. Many come with holders, but you can just place it on a slightly damp tea towel on the table. The stone should be roughly perpendicular to your body, though Warner told me it is sometimes easier to angle it ever so slightly to the right (if you're right handed). 
I enjoy these stones so much that the feedback is not a deterrent at all for me, I don’t even think about it. The results are always nothing but top notch, they deliver exactly what I want, some of the sharpest knives I have ever produced were sharpened on Shapton Glass stones. They may be thinner but they last a very long time, they are easy to maintain as well,
I purchased this set together with the 400/1000 grit stone assuming that some of my knives were quite dull and would need work on a coarse grit stone. Premium Whetstone Sharpening Stone 2 Side Grit 400/1000 | Knife Sharpener Waterstone with NonSlip Rubber Base & Flattening Stone. This is my first wetstone. First off I tried to sharpen my Chicago Cutlery boning knife. This knife is nearly thirty years old, has been abused in may ways and was quite dull. It was very difficult for me to get a burr on this blade, which I attribute to poor technique. Next I moved on to my Henckels Professional S paring and chef's knives. The paring knife was moderately sharp and was modestly improved after working over all three grits of stone. It would cut paper but again it was difficult to develop a burr with this blade. Undaunted I switched to the chef's knife. This knife is twenty years old and has never been professionally re-sharpened. I have sharpened it twice with a Lanksey sharpening system which marred the finish but did put a good edge on the blade. Lansky Standard Coarse Sharpening System with Fine Hones. The chef's knife was moderately dull and had several pits visible on the cutting surface. I modified my technique for passing the knife over the stone and worked the chef's knife over the 400 grit stone aggressively and eventually I was able to get a burr to form from the tip of the knife all the way to the handle. From there it was a simple process of reforming the burr on the 1000 grit stone and then finishing on the 6000. After sharpening, the chef's knife easily and cleanly slices a tomato with very light pressure and is in my opinion very sharp. Not sushi knife sharp but more than enough for the chopping and slicing I expect of it. I'm looking forward to going back and working both the boning knife and the paring knife over again. Don't expect a good result from this product the first time you use it. Watch videos on using a wetstone, expect to spend at least twenty minutes per knife at first, and practice forming a burr. If you can form a burr, you will be able to successfully sharpen your knife.