Skype is one of the best Video calling software,owned by Microsoft.Skype offer lot of features like Video call,Direct Phone call,Chatting and more.
Double click the downloaded deb file, it will open in ubuntu software centre, click the install button to install the application.
After upgrading your machine to the 64-bit version of Ubuntu 12.04 (Precise Pangolin), your Skype might not start. The problem might be caused due to a missing 32-bit library.
Run skype to see if it throws any error.
$ skype skype: error while loading shared libraries: libXv.so.1: cannot open shared object file: No such file or directory
Find the missing libraries using the ldd command.
$ ldd /usr/bin/skype
linux-gate.so.1 => (0xf7796000) libasound.so.2 => /usr/lib/i386-linux-gnu/libasound.so.2 (0xf767d000) libXv.so.1 => not found libXss.so.1 => /usr/lib/i386-linux-gnu/libXss.so.1 (0xf7678000)
Insatll the 32-bit version of the library
$ sudo apt-get install libxv1:i386