Recommended reading

• ‎The Unitarian Life: Voices from the Past and Present by Stephen Lingwood - a collection of pieces written by various Unitarians through the centuries; gives a good overview of Unitarian thought on many different topics. 
• The Larger View by Vernon Marshall - the history of how Unitarianism became open to other faiths.    
• Unitarian - What's That? by Cliff Reed - another overview, in the form of a Q & A 
• The Unitarians: A Short History by Leonard Smith - gives history of development of Unitarianism (but omits the Earth Spirit strand and most of Transcendentalism)
• Being Together: Unitarians Celebrate Congregational Life - edited by Matthew F. Smith 
• Unitarian Perspectives on Contemporary Social Issues - edited by George Chryssides 
• Unitarian Perspective on Contemporary Religious Thought - edited by George Chryssides
• Elements of Unitarianism by George Chryssides - overview plus potted history. 
• A Chosen Faith: An Introduction to Unitarian Universalism by John A Buehrens and Forrest Church. 
• Love and Death: My Journey through The Valley of the Shadow by Forrest Church 
• The Cathedral of the World: A Universalist Theology by Forrest Church 

You can buy some of these from the UK Unitarian website.

Unitarian Engagement Groups and Small Group Ministry 

Unitarian Engagement Groups - How to start and facilitate groups

Unitarian Christianity 

• David Doel, The Man they called the Christ 
• David Doel, That Glorious Liberty 

Unitarian Earth Spirit 

• Unitarianism and Druidry by Alastair Bate
• Pagan and pantheist tendencies in Unitarianism by Yvonne Aburrow