How do I connect a desktop printer to my Macbook Air?

I have recently become an apple member and I am still trying to find my way around my laptop. I have a hp desktop printer that runs off of my old PC and I want to be able to print wirelessly from my mac, can someone help me? I don't know where to start. My old laptop (not a mac) could connect and print wirelessly with ease but I am completely lost with this.