Start with high-confidence sysadmin books, then narrow by subgenre or adjacent topics.
Systems Performance
Brendan Gregg
Practice of System and Network Administration, the
Thomas A. Limoncelli, Christina J. Hogan
Network Troubleshooting Tools
Joseph Sloan
Essential SNMP
Douglas Mauro, Kevin Schmidt
JUNOS High Availability
James Sonderegger, Orin Blomberg
Data Center Handbook
Hwaiyu Geng
Virtualization Essentials
Matthew Portnoy
Networking All-in-one for Dummies
Doug Lowe
Using Mac OS X Lion Server
Charles Edge
Macintosh Terminal Pocket Guide
Daniel Barrett
Juniper QFX5100 Series
Douglas Hanks
Jenkins 2: Up and Running
Brent Laster
Wicked Cool Shell Scripts, 2nd Edition
Dave Taylor, Brandon Perry
Learn Powershell in a Month of Lunches, Fourth Edition
Travis Plunk, James Petty
