Try typing "apt-get lm_sensors" as su or root. It should download lm_sensors and install it for you. The command su is called switch user. It can switch you to root or to other users that you have added. It defaults to root. Type "man su" to learn more about su.
Below are some helpful sites to get you started in LINUX.
http://www.justlinux.com/
http://www.tldp.org/
http://linux-sxs.org/parent.html
IMO, Mandrake is much easier for novice LINUX users than Redhat. Mandrake is a lot easier when picking programs to install than Redhat. When I tried Redhat I feel that it is holding my learning experience back too much.