CentOS 7 is recently released. There is standart installation methods like from cd, network. I am gonna show you screen by screen network installation with netinstall.iso file.
Firstly download CentOS netinstall.iso from site.
Then burn it or set for virtual machine cdrom.
Select you installation language
Select your keyboard layout
Select your timezone
Decide disk and partition. You can use automatic (default) partition which is enough for most of situtations for personal use.
Bring up the network device which is a ethernet card here.
Add Installtion source
Than the metadata of packets will be downloaded to select software collections
I choose minimal installation buy you can select whatever you want
Now everything is configured correctly we can click to installation button
Add root user and password
Add user other then root
Everything is fine just wait
Installation is completed