Google - the best place to start. Just enter in a search like "networking linux" or something like that. After you've done some research, and found the plethora of tutorials, guides, and manuals for linux networking, then come back and ask questions for what you didn't learn.
Yes, knoppix can be networked. Linux was designed to be a networking operating system.
Yes, knoppix can be used in an office environment. Linux has several office applications very similar to Microsoft Office, such as OpenOffice. And you can network linux computers with windows computers.
