Governance for Unitarian Universalist Congregations is a handbook which has information about both the history and practice of governance.
Governance and Ministry: Rethinking Board Leadership, by Dan Hotchkiss (Alban Institute, 2009) and All Are Chosen: Stories of Lay Ministry and Leadership, Margaret L. Beard and Roger W. Comstock, eds. (Skinner House, 1998) are both available from inSpirit: The UU Book and Gift Shop.
Ask about visiting a Board or congregational meeting. Most congregations welcome visitors, though they may restrict participation of non-members.