This tutorial shows default Mac OS X Snow Leopard installation, everything is more less the same for Lion and Mountain Lion, just a slightly different changes in a design.
This is basic and default way to install OS X on Mackintosh machines (installing boot loader and after install procedures are not included cause this is only needed for Hackintosh computers)
So, first boot your copy of a retail DVD, or USB installation media with OS X on it.
When installation screen appears you will have to select your language and proceed to the next step.
When Install Mac OS X appear, click “disk utillity” from upper menu
Than choose your HDD, click on “Partition”, select one partition, name it the way u want and click on “Options”
Select “Guid Partition Table” and click OK
Now click Apply, and “Partition” and after a minute when it’s finished close “Disk Utillity”