A master machinist (CPO, pattern maker) taught me how to sharpen a knife. A 'razor edge' is too hard to maintain to be worth bothering with and usually cuts no better than a slightly jagged edge. Sharpen once every week or two on a medium fine stone and whet on a steel as needed. Remember to sharpen as if you were trying to shave the stone or the steel. The magnified edge should be about 60º, too steep an angle is fragile.

High carbon steel takes a much better edge than stainless but is harder to maintain. I prefer Sabatier and Haenkel. It's really a matter of what works best for you, though.