We recommend two options for this:
Both offer free plans that allow you to connect your blog to Facebook, Twitter, LinkedIn, Google+ pages and more via RSS feeds. Note: These free plans come with limitations on the number of feeds and social profiles you're allowed to connect.
Once you've created your free account with Hootsuite or Dlvr.it, you can connect your site's RSS feed to your social profiles by following the instructions below:
The RSS feed for your site's blog can be found at www.example.com/feed/.
Lastly, our team can take care of this for you through our Social Media Program which also includes Facebook, Twitter, LinkedIn and Google+ designs as well as monthly status updates written by our team and posted to your accounts for you. Learn more.