Sustainable growth happens in stages. Remember, as you increase the number of students and participants in an education program, you will need to get more volunteers involved both to support students and to develop tools, materials and platforms to manage the program more efficiently.
People:
Document your history and accomplishments - There is no replacement for local program history or real achievements. Use tools like the education extension and Wikimetrics to gather information about how much content students have created so that you have numbers to go with your story.
Retention of your teachers - before you start scaling your program up, make sure you devote enough time and effort to maintain the currently collaborating teachers. If they keep collaborating with your each school year, your program can then only grow.
Focus on growing your program at one institution at a time, this will make it easier to develop a network of ambassadors, and reduce the amount of travel neccessary for volunteers to visit classrooms.
Use social media: Sharing local stories about successful education programs on social media is a good way to both educators and volunteers interested in participating.
Train staff in libraries or ICT centers to support students and teachers. You may need to provide school administrators with metrics to show how many students students are involved in Wikimedia education programs in order to do this.
Recruit ambassadors: Ask former education program participants (or experienced Wikipedians who proved helpful in assisting students on Wikipedia) to help teach and mentor new students both online and in classrooms.
Tools:
Creating local portal: Local education portals make it easier to share training materials and organize participants at several institutions or ability levels.
Use the education extension: As your education program grows it is important to use an efficient tool to track student work.
Education program leaders have found that media attention helps grow awareness of programs Let the media know.