Go to Skype.com, and click 'Get Skype'. Now, select your operating System (OS) your computer is. Then click 'Download Skype'.
If you are a Android user, go to your 'Android Market'. Then look up 'Skype' in Apps. Then click 'Install'.
If you are a iPhone/iPod user, go to your app called 'App Store'. Search: 'Skype'.
Then click 'Install'.
Now, For the above instructions for all 3 of those options, You should see 'Dont have a Skype name?' some where on the application's startup. Click it. Then from there you follow the easy to use step-by-step instructions. Its that easy!