TwitterFeed Help File
From Wiki
Twitter Feed is a 3rd Party (free) service that allows you to autopost any RSS feed to Twitter, Facebook, and Linked in.
Here is a video helpfile that shows you exactly how to connect twitter feed to the available social media accounts:
How to connect an RSS Feed to Twitterfeed for AutoPosting to Twitter and Facebook.
You may grab a free TwitterFeed account here.
Also See One Feed To Rule Them All