To install WebGUI on a standard RedHat 7.3 machine you have to download the files from SourceForge listed under RedHat 7.3 packages.
Make sure you have all files including the perl ones.

Prerequisits

To be able to install you have to have Apache, mod_perl, perl and mysql-server installed on your target server, these are provided on your RedHat installation media, and are installed on most RedHat systems.

Step by step

Step 1: Activate mod_perl

First of all, make sure that mod_perl is activated in Apache, to do this you have to edit /etc/httpd/conf/httpd.conf and make sure that the lines activating mod_perl is not commented out. To do this simple remove any hash (#) at the begining of the lines.
The should look like:

<IfModule mod_perl.c>
    Alias /perl /var/www/perl
    <Directory /var/www/perl>
        SetHandler perl-script
        PerlHandler Apache::Registry
        Options +ExecCGI
    </Directory>
</IfModule>

After you have modified the configfile it is required that you restart the web-server. To restart it type:

service httpd restart

Step 2: perl modules

Next you should install the perl modules required to start WebGUI. Asuming your standing in the directory where you downloaded the files from SourceForge and your root type:

rpm -Uvh perl-*i386.rpm

You should see how the rpm's are installed without any error.

Step 3: The actual WebGUI rpm

This is the actual step to install WebGUI on your server. Assuming you have mysql-serve up and running it will create the default database for you as well as configure WebGUI so that it is instantly avaiable on your webserver.
Make sure your still root and then type:

rpm -Uvh webgui-*noarch.rpm

Thats it, you now have a fully up and running WebGUI on you server, simply point your webbrowser towards http://YourServerIp/perl/webgui.cgi 

Make sure as you do this as soon as posible since the system uses the default user & password, so you should change this as soon as posible.

Rooms for improvement and general comments

Right now the download does not have the necesary perl modules to enable SMB authoentification,nor activating the preload.pl file, this packages will be made avaiable for RedHat 7.3 in a short time.

If your upgrading via RPM you get a bunch of ugly printouts, they are not problems, but should probably be cleaned up.

This is not an official release by PlainBlack, they are packed by Tocobob and any support issues regarding the actual RPM (Not WebGUI in it self) should be directed at him.