Do you mean the files and printer are on the Mac and you want to connect to them from the PC, or the other way around?
If you're sharing files and such on the Mac, you will need to make sure that Windows file sharing and printer sharing are turned on on the Mac.I haven't used Snow Leopard, but in Leopard when you turn on file sharing, there is an Options button, and you must click it and check the option to share files using SMB; SMB is Windows sharing, and Windows can't "see" the Mac unless SMB sharing is on.
The Mac and Windows computer must also both be set to the same workgroup. See what your workgroup setting is on the Windows computer. Then, on the Mac, click System Preferences, click Network, click Advanced, click the WINS tab, and make sure the Mac is set to the same workgroup.