Administering the system includes, but is not limited to, various tasks like user management, pruning the excess software packages installed on the system, and general maintenance that keeps a server secure and in good shape. Remember that these books are not a substitute for hard-work, a curiosity, and hands-on experience with Linux. Another thing to remember is that everything changes quickly in the world of Linux. Therefore, it is of utmost importance to keep updating yourself with new knowledge and buy books that are not more than a few months old, unless they're recommended by many people and have stood the test of time.
Linux Administration Handbook (2008) - Evi Nemeth, Garth Snyder, Trent R. Hein: This is one of the most important books you can buy. With a positive review from someone like Linus Torvalds himself, you cannot go wrong with this one. The authors expect you to know a thing or two about Linux and take it from there. The content is well written and packed with information, and covers most of the major Linux distributions in use today - Ubuntu, Fedora, Red Hat Enterprise, Debian. The content is not just a bunch of 'man' pages lined up one after another, and care has been taken to keep the content fresh and at times, humorous. You can use it as a start-to-end book or use it as a reference whenever you're stuck with something. All in all, a highly recommended book for system administration.
