The answer is yes you can, and you might already have the software on your machine to do this. There are many ways to create local area networks with your computers and printers using the same ethernet connection you use to reach the internet. This type of network can be set up with Windows for Workgroups, Windows95, or Windows NT Workstation on PCs. This can also be done using Appletalk on the Macintosh. You cannot specify who can access these folders, but you can specify a password and only give it to those who you want to give access to.
Printers can be setup in much the same way.
A peer network of any of the aforementioned operating systems will likely be troublesome unless you are only exchanging files and sharing printers. This is because each user is at the whim of the others. If you want to move beyond peer networking, you will want to get a Network Server Operating System . With a Network Server Operating System, a file server can often be a dedicated or non-dedicated machine. This is not true with the later versions of Novell Netware which require a file server to be a dedicated machine.