The left panel on a Facebook page starts with your profile picture, followed by links to the sections of your page, your About information, your likes, and various other links for updates and sharing options. Visitors to your Facebook page see the same content in the left panel.
The left sidebar of a Google+ page places a drop-down menu next to the profile picture for switching between your personal and business pages. It also has a link to the getting-started page, as well as a list of your circles for filtering your incoming stream. Visitors to your Google+ page see a list of your followers on the left, along with a button to share your page or to give it a +1.