I'm Windows/Windows Server user and if I could install Ubuntu server anyone can
All you have to do initially is to install Ubuntu with OpenSSH option during install. After that you can do all other stuff from console by using something like PuTTy:
Why? It supports copy/paste so you can copy/paste all commands from tutorial. That way you will eliminate typos because those are the major problem for most users and those errors are hard to track down.
All updates to Ubuntu can be done by two commands from console(PuTTy):
apt-get update - gets info about new updates
apt-get upgrade - actual update procedure
and you are done. Do this one or twice a week and you will have fully updated system.
Similar can be done in most Linux Server Distributions but I have worked only with Ubuntu.