First of all you have to get the latest release of Skype. Link to download page
At the moment there are three choices to pick for download. Choose the one that matches the type of architecture your OS support 32-bit or 64-bit software. Even though the one’s listed are for 8.04 & 8.10 versions of Ubuntu, they will work for both 9.04 & 9.10.
When you choose the one that will work for your system. Choose to save the file to the Desktop, or where it is most convenient for you.
If you notice at the end of the file there is a .deb extension, that extension will cause the package manager to open and start installing the application, checking first that all dependencies are met for the application to run properly; then asking if you would like to install the application.
Next double click on the file that was downloaded from skype. It should look something like this.
Once you double-click the package for Skype you will get a window that will show that all dependencies are met, if not the packages will automatically be downloaded when installing the package.
*note there will be a install package, not reinstall package on the top right hand corner, if you have what is in the image, you already have Skype installed.
After it is installed, you will find the application in the Applications Menu, in the Internet menu. Just select Skype, put in your login and password for Skype; and now you can contact anyone that has a Skype account. Windows, Macintosh, Linux, or Mobile, no matter what operating system you have or the one’s that you wish to contact. That’s the great thing about Skype, you just need access to the Internet.
If you don’t have a Skype account yet you can get one here – Skype