1) First lets deal with the server. You need to decide what functions the server will have (eg. file, email, proxy etc.)
-usually for simple file sharing you can designate one of your PC (workstation) to be the file server ( you can still use it as a workstation)
-for email and or proxy I would suggest using linux for both proxy(internet sharing) and email this is because of cost ( almost free) and ease of config and use. You need a dedicated PC for this. Separate from your current 8, or use one of you existing ones and have 7 workstation left over.
Having decided this you can then look at the network.
2) Network configuration-client-server type
-Today the simplest (take note**not the only one) would be to use a hub/switch and connecting your workstations using UTP cables (CAT 5e or CAT 6) data cables. Refer to this link on networking http://www.duxcw.com/digest/Howto/network/cable/
- You have to make sure that ALL your workstations have network interface cards (nic's) to connect to your network.
3) Internet connection
-You can use the proxy server you would create for this purpose or to make it simpler just purchase a broadband router. Choose one that has DHCP capabilities so you dont have to worry about setting IP addresses for your workstations.
4) For the operating system
a) Workstations - Linux or XP pro
- Linux
Pros
Freely downloadable (ubuntu, freespire etc)
includes Office type software.
Network ready
not easily infected by viruses
Cons
Higher learning curve than windows
may require "tweaking" to get everything working
-Windows
Pros
Popular OS
More software available
Generally compatible with most devices
Support readily available
Cons
More prone to hacks and attacks
Dependent on patches and updates
High hardware resource requirements
Really it all boils down to what you need, if the above suits you you will need the following hardware:
1) Enough nic's (network interface cards) for your workstations
2) Hub/Switch ( 8 or 16 ports)
3) Broadband router (for internet sharing, if you do not use a proxy linux server)
4) Cables (UTP) and rj45 connectors
5) UTP crimper
6) A lot of patience to make this work.
This is the minimum you will need. BTW, if you do decide to just have everyone share each others hard drives and printers (peer to peer network) just remember that everyone should have the same workgroup name.
Hope this helps.