Don't forget 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?

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".
• Administrators should use "secure browsing only" for their personal accounts
• Activate "Login Approvals". You will have to enter SMS code or Generated code, once you would like to login to Facebook from unknow device.

Twitter

• Connect your phone number and your account so you can reset your password if your account gets compromised.
• Check out which applications have access to your Twitter account.
• If your account gets compromised, here is what you can do: https://support.twitter.com/articles/31796#.

Google+ and other GoogleID related apps

• tba