Well. you are going to have to provide more significant details first about your network. HOWEVER. we can save all the troubleshooting between all Operating systems, Network Protocol, Firewalls, workgroup names, sharing, and router configuration, if you upgrade to the latest d-link firmware, download the shareport software, plug your printer into the usb port of the router (hoping your printer has a usb connection) and install the shareport clients on all computers. It makes life a lot less complicated.
Otherwise.
Each compututer must have a unique name.
Each computer *should* be within the same workgroup.
All firewalls (for the time being) should be disabled. Don't worry, the router is protecting you. If still concerned disconnect the WAN cord on the router.
For any wireless computers, you will have to make sure that in the router, Advanced> Advanced Wireless> that the WLAN Partition does NOT have a checkmark in it. You may want to have WINS enabled in the router as well. (no need to learn from WAN, that's a bad idea)
Now, after the router has done all its' reboots (reminds me of winxp after every configuration change), I want you to open cmd on every computer. On the first computer, ping first the IP adress of all other computers. Then repeat the steps with all other computers. Then I want you to ping the computer names of all computers from every computer. Then you need to make sure that on every computer you can browse the network and see all computers.
Then, on every computer, you need to make sure that in services.msc that print spooler is enabled.
Then on the main computer hosting the printer, you need to make sure that in the printer properties, that sharing is enabled for that printer.
Then on every computer, you need to "add" a printer. go through the wizard, select network printer, and then browse the network for the printer, you will need the drivers for every computer. Then if successful, open up notepad on every computer and just type, "test" and then print. And see if every printer can print. to save the tree's, use the same page over again, flipping and rotating it after each print, just so you can verify every computer is printing the workd "test".

that is your steps in a nutshell. LIke I said, it can get very detailed especially with the troubleshooting.
which is why I suggested shareport first.
