What is the Baha'i Faith? Who is Baha'u'llah? What are the teachings of the Baha'i Faith? The Baha'i Faith: An Introduction by Gloria Faizi, offers a very accessible introduction to the Baha'i Faith, it's history, teachings and structure.
Since 1971 this little book has been used as the introduction to the Baha'i Faith. It has been translated into at least 21 different languages, and had millions of copies sold.