What should a community manager do to optimize their work routines regards to volunteers?
The best advice here is to treat your volunteers as a community within the bigger community and act accordingly.
Once there are a few active volunteers in the community (usually 5 - 10 people), maintaining relationships with each volunteer individually becomes difficult and time consuming. You need to create a dedicated space only for volunteers where you can communicate to all of them at once and volunteers can interact with one another.
Everything that is true for an online community in general is also true for a group of volunteers (goals, tools, etc.). The main nuance is that the mission of the sub–community of volunteers is always the same - to make the community successful.
This is a fragment of a draft of the book “Lessons Learned While Working On Stack Overflow”. Read the full book on kindle or the paperback version.