I have a wireless cablemodem router that I have a desktop connected to through a cable and I have a laptop connected via wireless connection. I have no problems with the internet on either.

I am wondering can I do a file/printer share through the router? I would like to be able to print from both without having to switch the printer cable between them. I would also like to be able to access an external hard drive from my laptop that is currently connected to the desktop. Is there anyway to accomplish this with my current equipment or do I NEED something else?

Thanks for your help.Yes it would seem that you already have all you need. Ensure both machines are members of the same workgroup. Right-click on the items you wish to share across the network (folder or printer) and use the "share" option. Google "Windows file and printer sharing" for more...I like to add some additional notes from my experiences if I may:
-The printer should be connected to the hardwired Desktop only. Switching a printer between two machines is not favourable. From my TRYOUTS, it appears that (somehow) the printer itself will be setup for the one, that will (then) not fit on the other (even with having software installed on both). There my be issues such as different operating systems (XP, W2K). Having a dataswitch does not always help. The printer will be momentarily unplugged and causes the the system to hang. The same is true for unplugging the printer and PLUGGING it into another machine while the system is running. This will throw a message "hardware UNSAFELY unplugged" and the system will hang.
-make sure to "share" the printer under some "ShareName".
-There is NO need (at least on my "MicroSoft WindowsNetwork) to be one and the same Workgroup in order to access other workgroups shared files, drives and printers.
I hope this is of benefit.
Thanks for your help!! I got it working last night! I don't know what I was doing wrong before, it seemed QUIT easy last night. I appreciate your help.