The Father, Son, and Holy Spirit, by Bruce Ware, is a great resource for learning more about the biblical understanding of and practical implications for the Trinity.  In under 160 pages, Ware provides a very readable, yet incredible thoughtful look at this orthodox Christian position.  Here is a snippet to wet your taste buds:

“The doctrine of the Trinity affirms God’s whole and undivided essence belongs equally, eternally, simultaneously and fully to each of the three distinct Persons of the Godhead.

Equally so as to avoid Arianism. 

Eternally so as to avoid thinking of God’s nature as created.

Simultaneously so as to avoid modalism.

Fully so as to avoid any tri-partite understanding of the Trinity.”

(From page 41)