What is Theology - Theology is simply humanity's attempt to understand God as He is revealed in the Bible.
A Compendium of Christian Theology in Three Volumes by William Burt Pope, D.D.,
Fundamental Christian Theology, Vol. 1 by Aaron Hills
Fundamental Christian Theology, Vol. 2 by Aaron Hills
Systematic Theology Volume 1 by Rev. Charles G. Finney
Systematic Theology Volume 2 by Rev. Charles G. Finney
Systematic Theology Volume 3 by Rev. Charles G. Finney
The Christian Faith Personally Given In A System of Doctrine - by Olin Alfred Curtis
Essential Christian Beliefs by Stephen Solomon White
Manual of Theology By J. L. Dagg, D. D.
Types of Theology
Systematic Theology - That branch of theology which deals with the logical categorizing of Biblical truths by tracing the self-revelation of God through the Scriptures as a whole and then carefully organized by doctrine.
Biblical Theology - Interpretation of the Bible, often with particular emphasis on links between biblical texts and the topics of systematic or dogmatic theology.
Historical Theology - Historical theology is the branch of Christian theology that focuses on the biblical and systematic theology of theologians of the past.
Moral Theology - Moral theology is the branch of Christian theology that addresses questions relating to how Christians ought to live.
Liberation Theology - (Including one of it's branches called Black Theology or Black Liberation Theology) 100% Unbiblical - a school of theology that focuses on Jesus Christ not as the Redeemer but as the so-called "Liberator" of the oppressed - Only used by Liberal non-Christian churches who attempt to mix Christianity with Marxism