It’s easy.  Sign up as an individual and select to be a volunteer.  Then  have a diary reminder to do an hour weekly or monthly or whatever suits.  Here are some things to do that will help grow SustainableSocial.org:

• Invite friends to sign up.  Suggest they also volunteer – that will really accelerates things. 
• Post each week to your page and share the post to Facebook or Twitter.  
• Contact to businesses in your area via Facebook, Google search to their webpages, yellow Page etc. and invite them to get on the directory, it’s free, share this link with them.  You may like to use some of this text for Cafes and Restaurants   Hotels and Accommodation and Other Businesses.  
• Try to get one message each week out to one famous person – a singer, sports star, blogger, Youtuber, journalist – who ever you think of – if they share it will supercharge your impact.