Can anyone tell me how to set up a server?

First off, this is all opinionated. There is no right or wrong answer when it comes to setting up a home based network, or even a business network. It will be fit for your needs. Id purchase a computer, or build my own, with server 2003 standard edition sp2. Buy a cisco router, and cisco firewall, for networking purposes.You will have to install active directory on your server 2003 machine which is a database that holds user accounts, file-print servers, passwords, etc. Before installing AD you will have to set up a DNS server, and or DHCP server if you will want your server to hosts IP addresses' if not, and it will be the cisco devices you do not have to configure DHCP. DNS is required on your server before installing active directory. I would google video's tutorial's and other media to be able to get a better idea of how to set this up. You will also need to decide what IP address ranges you will want to use internally, class a, b, or c. class A being 10.x, class B being 172.x, and class C being 192.x These ip address ranges will be based on how many devices you will have and be having in the future.