Which version of Linux should I install on my laptop? I am a begginer.
go for lubuntu
Ubuntu all the way dude, listen to the wise guys above.
Since you are a beginner, I'd suggest (like everybody else), Linux Mint first and then Ubuntu. I personally prefer Ubuntu over Mint, but the point here is Mint works out-of-the-box and is compatible with Ubuntu. So, go for Mint, which is based on the most popular Linux distro (Ubuntu) and is the 4th most widely used desktop operating system! (as they claim in their installer!)
I found that Linux Mint or Mepis are good starting points for getting into linux
You can also try Linux MInt (a Ubuntu variant). Some say that it is even more user-friendly than Ubuntu.