I got inspired by the 10 commandments for system administrators from http://www.linux.com/feature/44315
This is my list:
1. Be WARY about COST CUTTING.
(cheap hardware, cables, labour)
2. KNOW THE NETWORK well.
(keep network, routing diagrams, track public and private IP, label cables if necessary)
3. ESTABLISH STRONG SECURITY POLICIES in the system.
(Security Access, File Permission, good password choice, encryption, SetUID, LDAP, Kerberos, IPA, firewall)
4. Be the FIRST TO KNOW when something goes wrong.
(Network monitoring, Nagios, SMS, email alerts)
5. make REGULAR and COMPLETE BACKUPS.
(dd, scp, rsync, disk mirroring, backup virtual image, SVN)
6. KEEP LOGS.
(apache, maillogs, audit)
7. BE ORGANISED and DOCUMENT policies and procedures.
(twiki – how and why to do things, keep charts, flow diagram, important phone numbers, important dates)
8. PLAN FOR THE UNPLANNED.
(recovery procedures, possible points of failure, redundancy, always have a plan B for any implementation)
9. AUTOMATE REPETITIVE TASK.
(bash/perl scripting, cron)
10. UPGRADE and EXPLORE NEW TECHNOLOGIES.
(Don’t stick to old technologies. Always be ready to upgrade both software and hardware wise. Have a few test machines to explore new technologies and implement them.)