I am complete newbie when it comes to running a server but have a bit of experience using Ubuntu in my local box. Is ubuntu a good choice? Since most use a flavor of Red Hat like CentOS I am a bit hesitant to use Ubuntu in production.
Ubuntu and debian are used by plenty of people in production and are probably the better choice for learning how to set up a server if you already use ubuntu.
Apt is also a great package manager.
It could well be that I'm biased--and you should certainly go with what you are comfortable if this is to be a one-man show--but in the pony show that is choosing a server OS, I'd go with Debian every time.
(I'm an Arch guy these days, but hey...)
Pacman and apt are both better imo, and apt-get build-dep is really great when you need to do a source install but can still use normal dependencies.
(I do use aptitude now instead of apt though)