It's very important to:

• Use a different username and password for different Social Media services. Don't forget the LinkedIn incident.
• Have a plan for the case of account hijack. What are you going to do. Do you have your account connected to the mobile phone for password retrieval?
• do you use double security check (password+confirmed desktops) on Google+ and other google connected accounts.

Facebook

Site administrators will have to use their personal accounts to be productive. Period.

• Be aware who in the company has the privileges to publish on FB as your NREN.
• Asign your staff different administrative roles like "Content creators" or "Moderators" instead of "Managers".