Sounds to me as if your network is not set up properly...if you cannot see the other members of the workgroup.
As for a printer or any other shared resource....the network must be set up properly first...then the resource must be properly shared.
When I have problems, I just set the network up anew and double-check the protocols...that solves all of my self-imposed networking situations.
How to Share Printer in Windows XP - http://www.home-network-help.com/share-printer.html
Have you looked at any Win 7 HELP menus on these subjects?
Edited by hamluis, 21 December 2009 - 09:34 PM.