Unix/Linux TOP command Fully explained here. Very good information. Kudos to Prabhat Kumar. Check out comments too.

http://adminlinux.blogspot.com/2009/06/how-do-i-use-linux-top-command.html

A short and informative explanation on Linux run levels and startup scripts. Thanks to Joshua Erdman.

http://www.networkclue.com/os/Linux/run-levels.aspx

A Detailed look at the boot Process
http://www.redhat.com/docs/manuals/linux/RHL-9-Manual/ref-guide/s1-boot-init-shutdown-process.html


Inside the Linux Boot Process
http://www.ibm.com/developerworks/linux/library/l-linuxboot/