You can install Adobe flash player by visiting the official Adobe site. You can download rpm file from the same site. For 64 bit system I recommend a preview release of flash player with native support for 64bit Linux.
Step #1: Download Flash Player
Visit any site such as youtube.com and you will see the following message on screen:
We support browsers that support both the video tag in HTML5 and either the h.264 video codec or the WebM format (with VP8 codec). These include: => Firefox 4 => Google Chrome => Opera 10.6+ => Apple Safari => Microsoft Internet Explorer 9 => Microsoft Internet Explorer 6, 7, or 8 with Google Chrome Frame installed (Get Google Chrome Frame)