Get the debs from here.
Once you have downloaded the deb file , double click on the file. The gdebi package installer will be started and it will ask for your password. Follow the on screen prompts and finish the install.
You can add skype to your start up as below.
Go to "System -> Preferences -> Startup Application", Click "Add" and enter the following details:
Click on Save. Next time you start your system Skype will auto-launch.
Enjoy using Skype in ubuntu