Step 1. Go to your Google+ page. https://plus.google.com
Step 2. Find the Invite Friends link on the page
Step 3. Select All and Copy the link provided. (Hint: right click on the text edit field.)
Step 4. In Facebook, Click Status, type your message.
Step 5. Paste your URL and click Status AGAIN. Facebook tries to change the post type to Link; however, the url is https so FB isn't going to show a decent description.
Step 7. Click Share.