Advice Needed re Home LAN, etc.

I am without a clue as to setting up a LAN. On the other hand, there are reasons why I will have to. The two computers run on different OSs, mine being on Linux and hers being on another kind, not to be named. Where can I get advice as to how to set up a home LAN (2 computers) attached through a telephone line to the Internet? Thanks dj tuchler