I bought a new Dell 660s for learning Linux! It is Intel i3, 4 GB, 500Gb HD, 23" dell led display and a nVIDIA GT 620 video card. I chose Ubuntu 12.04 LTS amd64. It is freshly installed.
I added a PPA source (see https://launchpad.net/~ubuntu-x-swat/+archive/x-updates) and installed the package nvidia-current and then rebooted.
The video card works on 1024x768, instead of native 1920x1080. Only resolutions of 1024x768 and 800x600 can be chosen in the system settings. Even worse, when I Ctrl+Alt+F1 to F6, all the ttys are blank. In fact, I tryed many times and read many texts online. All I can do now is to try to ask here for help.
I changed driver from ppa:ubuntu-x-swat/x-updates to ppa:xorg-edgers/ppa (see https://launchpad.net/~xorg-edgers/+archive/ppa). And installed the post-release one.
Now desktop display resolution is better. And now, I press Ctrl+Alt+F1 to F6, the screen is not that blank but changed to a black screen with only a blinking prompt as '_'. The TTY is not working still.