In general, networking is done for specific purposes including but not limited to;
- - centralised data storage and sharing
- - centralised data backup
- - provision of an email server with associated backups
- - printer sharing
- - internet connection sharing
- - data security (access rights etc.)
- - provision of an intranet
- - application sharing e.g. web-server based
Which of these (or any others) do you need to do? A lot of the roles above can be done on a standard OS but should be done on a server OS. You have that option immediately open to you with your linux box.