Who was the author? By Divine-inspiration the account was recorded by Mark (also known as "John Mark" or just "John"), who was likely from a family known to Christians in Jerusalem (see Acts 12:12) and who at different times worked with both Paul and Peter.
What is the book? The early church fathers tell us that the Gospel account bearing Mark's name was the content of Peter's preaching (see a rough outline in Acts 10:37).
Where was it written? Mark's account of the Holy Gospel was likely written in Rome and intended for the churches there, as well as for other primarily-Gentile hearers.
When was it written? Although there are various theories, Mark's account of the Gospel was likely written in the 50s or 60s.
Why? The Gospel may have been written as persecution in Rome increased (perhaps even as Peter's own martyrdom seemed imminent) in order to keep the Lord's suffering before the believers so they could follow Him in their own suffering.
How? The account unabashedly teaches Jesus Christ as the Son of God Who Himself taught His followers, by word and deed, to follow Him Who suffered for them.
For further reading on the book of Mark:
- Lenski, R. C. H. The Interpretation of St. Mark's Gospel. Minneapolis, MN: Augsburg Publishing House, 1961. (First published in 1946, Lenski's commentary is out of date as scholarship goes, but his interpretations are generally reliable and quite accessible to most readers.)
- Taylor, Vincent. The Gospel According to St. Mark: The Greek Text with Introduction, Notes, and Indexes, second edition. New York: St. Martin's Press, 1966. (Also now a bit out of date, but still a standard more-scholarly commentary, although also more higher-critical.)