If you are reading this guide and you know nothing about Sitecore, then I would recommend reading the first part of this article http://jondjones.com/how-to-install-sitecore-7-for-beginners/. As long as you have a valid Sitecore license and the Sitecore 8 installer, then we are good to go.
When you run the installer, the first screen you will see is the welcome screen, skip past that
Agree to the T&C’s
Select your install type. For a brand new build you want to select ‘Complete’
Add your license file
Add your SQL server details
Add the destination where you want to install Sitecore
Add the ISS host name. The installer will also add an entry in your host file
Then sit back and relax.
When the installer has finished doing its thing, your new Sitecore 8 website should load.
Sitecore 8 looks a lot different than version 7. By default you can log in with the user name ‘Admin’ and the password ‘b’.