Tutorials on linux sym admin

Some nice tutorial/online book on linux system administration:

http://tldp.org/LDP/sag/html/index.html

http://tldp.org/LDP/lame/LAME/linux-admin-made-easy/index.html

http://www.yolinux.com/TUTORIALS/LinuxTutorialSysAdmin.html

http://www.linuxtraining.co.uk/download/new_linux_course_modules.pdf

http://www.ee.surrey.ac.uk/Teaching/Unix/