I think you're looking for automated network installations.
To achieve this your should implement a netinstall server. There are a plenty of resources over the web to do this, and depending on the Linux Distribution you're using there are some specific tools, like mrepo
for RHEL based systems and apt-mirror
for Debian ones.
But in any case you'll need a PXE server to handle the network boot and extra services to serve files over the network, like TFTP, HTTP or NFS.
To make completely unattended installations you must create answer files according to your distribution, and a local mirror using the tools I've described is a good idea if you're deploying a lot of servers.
Since I don't know which distro you're using here are some references for the bigger ones in the enterprise:
Debian PXE Server: https://wiki.debian.org/PXEBootInstall
CentOS PXE Server: http://wiki.centos.org/HowTos/PXE