How to install OS X Yosemite 10.10
Phase 1: Boot up your Mac from the bootable installation disk.
Select in which language you want to install the system. The language can still be changed after the system installation.
Select “Disk Utility” to create a partition to install OS X.
Select your hard disk or SSD at the top the list on the left.
Change the keyboard layout by clicking on the upper left flag and select your keyboard layout.
Select “1 Partition” in the scroll menu.
Give a name to your Partition and click on the “Apply” button.
The system will ask you if you really want to create a new partition. Click on the “Partition” button.
When the new partition has been created, you can close Disk Utility by clicking on the red dot on the upper right corner of the window.
Select “Install OS X” in the OS X Utilities menu and click on “Continue”.
Just click on “Continue”.
Read the license agreement and click “Agree”.
Select the drive on which you have just created the new partition and click on “Install”.
The system start to copy the installation files on the disk. When the process has finished, the Mac will reboot.
Phase 2: The Mac reboots and the installation process begins.
After the installation process, the Mac will reboot once again.
Phase 3: The Mac reboots and the configuration process begins.
Select your country in the scroll menu. If you cannot find it, just click on “Show All” and select the right one.
Select the keyboard layout you want to use.
Select “Don’t transfer any information now” and click on “Continue”.
If you have an “Apple ID”, you can sign-in here or do it later.
Read the license agreement and click on “Agree”.
Type in your username and password and select an image for your profile. Click on “Continue”.
If you want your computer to send anonymous info to Apple, select these options. Click “Continue”.
Here is the final screen of the configuration process.
Now, your Mac is ready to go. Have fun!