With Linux an application update usually has to go through the operating system. The Application does not update out side the O.S like windows. Your best bet is to try to install it with an RPM file.An RPM file is like an exe. file for windows. http://www.google.com/search?q=Skype...8733203d1b4e27
If you can find a RPM file that will work ,Download it. When you click onto it a menu should appear (Installer this or that) and then click to install.
Opera Browser installs just as I have stated but when I put on Firefox it was harder. I had to use a Source RPM file which is not the greatest for a novice but not as hard as compiling it yourself like a source file. It is probably better to install Opera than Firefox. It is not as fast but is more stable.