This page contains links to helpful resources for churches considering or planning a congregation-wide sabbatical.
Wheatland Grant (Not clear if this is still available, but it has a lot of really great info in the PDF file)
Articles to Read
Renewal Time: Planning Your Sabbatical (Near bottom, mentions congregational sabbatical)
The Sabbath by Rabbi Abraham Joshua Heschel (not about Sabbaticals specifically, but Sabbath in general – filled with beautiful, inspiring, profound truths about the Sabbath.)