Go to Network and Sharing Center and turn on "file and printer sharing". Then share your printer. You may also need to add the other PCs in Advanced Sharing.
This worked perfectly for me. Gateway Tower, Windows 7, Canon Pixma MP210 All In One Printer/Scanner Connected by USB to tower.
My tower is connected directly by ethernet to my time warner surfboard modem. I imagine this WIKI HOW link will work for most inquiring about this subject who can or do connect their laptop or desktop to their wireless modem via ethernet. No separate print server needed. Simple as 1-2-3.
Don't let the router in the link throw you. If you have a wireless modem with more than one port you have a router. Good luck. It's easy. http://www.wikihow.com/Make-a-Printer-Wireless-With-a-Wireless-Router