Why do you need to sharpen knives? A sharp knife stands less chance of slipping on the material being cut and, because it requires less effort and force to use than a dull knife, you’re less likely to cut yourself. Working with a sharp knife is faster and easier, too. It also damages the material being cut less — ever tried to slice a tomato with a dull knife? It doesn’t exactly produce clean results.
Source: How To Sharpen Any Knife
It’s a long and thorough article, with a couple of supplemental videos (which can be over 5 minutes). It’s not dull… They cover angle, and suggest various options for sharpeners. What the article doesn’t cover is the difference between sharpening and honing:
Running your knife over a honing steel does NOT sharpen your knife. There, I said it.
Sharpening a knife can only be accomplished by actually grinding or shaving off tiny bits of the blade’s metal, giving the blade a completely new edge. You need professional sharpening equipment or a whetstone, literally a piece of stone with a grainy surface that you wet before running the blade across it to sharpen a knife’s blade.
What your honing steel does is help keep the blade straight.