The best thing to do is to set up a homegroup and you will be able to share files, printers, etc. This article goes through it plainly step-by-step.
You say that you would prefer to use the printer without turning on the desktop. To do this you could either see if it is possible to connect your priner to your router by ethernet or usb - not all routers have this facility. Alternatively, as you say, you could set it up wirelessly, assuming it has a wireless function - it will then be available to all pc's on your homegroup - this article will take you through the set up.