Before you jump in and install a disto, there are some things to consider, including: – Are you used to Linux? Do you know it well? Choose a distribution that suits your Linux knowledge. – Do you want commercial support? If so, make sure you pick a distribution that comes with support!
Debian is my current choice for servers, due to it’s wide use and simple upgrade process (“aptitude”). Some people seem to like “RedHat Enterprise Linux”, especially if you want commercial support. I find that RedHat EL systems are generally bloated, and require more fixing initially – whereas if you can use Debian, you can get a very minimal system and add on as you need it.
I’m not going to run you through the entire installation proccess, but installers these days are quite simple and documentation is easily found on Google. With Debian, my choice is a minimal install, or depending on the situation, a netinstall or commonly a bootstrap install (where Debian is installed using “debootstrap” from within another Linux distro).