To install Red Hat Enterprise Linux 5, set your your CD/DVD drive to boot first, to do this enter your systems bios and set the cd/dvd to boot first then save changes.
Insert your Red Hat Enterprise Linux 5 in your CD/DVD drive and restart your system. After restart Red Hat installer should boot as shown in the figure below
Select the type of installation you require. In this example we will be using the graphical mode installation. Hit enter key to start the installation. On the welcome screen the installation process will prompt you to check and test your installer. Select OK to test your media, otherwise select skip to continue installing Red Hat
On the Graphical Interface of red hat installation, click on the next button.
You will be asked to select you language, select your language and click next, on the next window select your keyboard layout and click next. You will be prompted to enter your installation number if you have one enter it, if none select skip entering installation number and click ok.
After these selections you will see the hard disk partitioning section. Select the Use free space on selected drive and click next. In the network devices window set the hostname to automatically via DHCP and click next.
Select your region or location on the next window; you can click on the map for your location.
Enter the Root password on the next window, Root is the administrator account for Linux operating systems.
The succeeding steps will be on the selection of additional packages to be installed on your Enterprise Linux Operating System.
After selecting these additional packages, installation of the operating system and these additional packages will begin, wait for the system to finish the installation.
After finishing the installation follow the instructions on the screen. You will be asked to configure your firewall. Select enabled and select the services you need to pass through the firewall. You can also add TCP and UDP ports.
On the SELinux window select the Enforcing option and click forward.
On the next window uncheck the enable Kdump option and click forward. Set the date and time in the Date and Time Window. In the software update set up, select yes if you want to connect to the Red Hat website for updates. Select no if you do not want to connect or plan to connect at a later time.
Create you preferred username and password in the Create User window then click forward. You can test your sound card in the next window. After that you will be asked to insert additional CD’s to install. If you don’t have any click the finish button. Your Linux Enterprise 5 operating system is ready to use. You just need to login to the system and start using Linux Enterprise 5 operating system.
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Check the link in your signature.

How can you have a website in your signature about using Linux and still asking for a link on how to install Redhat??

Btw: Practically installing linux is no different than installing any other OS. You download the os, burn it to a cd, boot computer from cd and follow the simple steps (Like clicking "Next", Checking the "I agree" checkboxes, Entering your computer name, Choosing a time zone etc.)

Here are some more infos:

Let me google that for you

Regards!