A: There are a total of 27 books in the New Testament written by 8 men (possibly 9: Hebrews unknown). They were written over a period of about 50 years from approximately 44 A.D. to 95 A.D. There is some controversy over the dates and order of these books, but most scholars hold pretty closely to the following order.
James
44 – 45 A.D.
Galatians
48 Or 49 A.D.
1 Thessalonians
Likely 51 A.D.
2 Thessalonains
51 Or 52 A.D.
Matthew
Ranges From 50 A.D. To 67 A.D.
Mark
Ranges From 55 A.D. To 68 A.D.
1 Corinthians
55 – 57 A.D.
2 Corinthians
55 – 57 A.D.
Romans
55 – 57 A.D.
Luke
60 – 62 A.D.
Acts
62 – 63 A.D.
Ephesians
60 – 62 A.D.
Colossians
60 – 62 A.D.
Philemon
60 – 62 A.D.
Philippians
60 – 62 A.D.
Hebrews
62 – 64 A.D.
1 Timothy
Likely 62 – 64 A.D.
Titus
Likely 63 Or 64 A.D.
1 Peter
About 64 A.D.
Jude
67 – 70 A.D.
2 Peter
About 67 A.D.
2 Timothy
Likely In Fall Of 67 A.D.
John
Likely 85 – 90 A.D.
1 John
90 – 95 A.D.
2 John
90 – 95 A.D.
3 John
90 – 95 A.D.
Revelation
95 – 97 A.D.
If you wish to know how some of these dates were arrived at, I explain in more detail in my New Testament Survey.