Newbie needs help to configure nagios


I am using fedora core 6 and found the quick start on the nagios website and got off to a good start until section 3 Compile and Install Nagios, first part of extracting the Nagios source code tarball was initially an issue as i did not recognise that i had to continue the command any way pass that and onto running the config script. This shows my lack of knowledge in this subject, so please help.

What is it that i am to do with the following
./configure --with-command-group=nagcmd

Please can someone fill in the blanks for me as it is obviously not what is written there.