A sharp knife is a safe knife. Invest in a sharpening stone, they are not very expensive (mine was $30) and when you realize how dull your knives have gotten you will be so happy you did. Not only are sharp knives safer, but they are also so much more fun. When your knife is gliding through a vegetable like you are slicing jello, food prep becomes a joy. 

How often you need sharpening depends on how often you use your knives. One day I decided to sharpen all of the knives in my home knife block and my knife kit (about 16 knives in all and some very dull) and I got through 2 full movies but now that they are all sharp I can do quick sharpening sessions as needed. You should hold your knife at a 22* angle against the stone pressing firmly and evenly on the face of the blade with three fingers, always keeping your thumb on the spine and all fingers away from the edge of the blade. I will post a video to demonstrate on my YouTube channel along with a short clip from one of my favorite teacher at The Culinary Institute of America.

Chef Cheng showing us the proper technique.

Also, the steel that comes with your knife block is not for sharpening, it’s used to hone your blade and that I use each time I use a knife to make sure my blades are straight. I hope you get as much joy from a sharp knife as I do and always- safety first!