A lot of printers would work. I recommend HP printers because that is what I use and they work great for me.
One of my favorite ones is the HP Deskjet 2543. You can print in black and color, you can copy, and you can scan. Connect it to the computer with a USB port and wait for the computer to recognize it, then you are ready to go. It also supports wireless printing. You can print something from your phone without any cables. How cool is that?