Ubuntu Server Edition, built on Debian GNU/Linux, has established itself as one of the most popular and well documented GNU/Linux server distributions. The Long Term Support (LTS) version of Ubuntu Server is provided with security updates for five years from the release date. This long term commitment ensures a stable base for deployment. Beginning Ubuntu LTS Server Administration From Novice to Professional aims to teach all you need to know to begin administering Ubuntu Server. The book covers installing, configuring and the systems administration tasks for Ubuntu Server Edition.
I'm a Debian user and--like many--I use apt and its associated tools. If you haven't yet discovered apt here's a brief summary of some of it and some of its tools which can make your package management even more powerful.
The Apache Tomcat server is the most well known and deployed Servlet container for dynamic Java based web applications. Pro Apache Tomcat 6 by Matthhew Moodie (edited by Kunal Mittal and published by Apress) explains in exacting, systematic and well covered detail how to manage the latest version of this high quality, popular free software product.
In my geek career, I have been many things: DBA, programmer, help-desk, engineer, systems administrator. I have worked with VMS, MS-DOS, various flavors of UNIX, MS-Windows of all sorts, OS/2, and MPE/iX. I have had a wide and various and satisfying career.
I can tell you without reservation, systems administration was the hardest and most demanding of all those jobs.
Linux is by reputation and in reality a highly stable platform. Being free software means that you can see its inner actions without the lead coat of proprietary license shielding. Problem determination with transparent source, if mastered within the Linux environment, enables the problem solver to focus efficiently on the issues at hand. New administrators tend to take longer to solve the more horribly tricky and very infrequent issues than those that have burnt their wizened fingers on the obtuse over the course of long years.