I am not sure how many people will read this but here goes anyway;The term 'apocrypha' was coined in the 5th century by St. Jerome, it refers to the biblical books included as part of the Septuagint (the Greek version of the Old Testament) but not included in the Hebrew Bible.
Several works ranging from the 4th century BC to New Testament times are considered apocryphal - including Judith, The Wisdom of Solomon, Tobit, Sirach, Baruch, 1st & 2nd Maccabees, the 2 books of Esdras, additions to Esther, the Book of Daniel & the Prayer of Manasseh.
The apocrypha have been variously included and omitted from Bibles over the course of centuries. Protestant churches generally exclude the apocrypha; Roman Catholic & Orthodox churches include most of the apocrypha but refer to them as deuterocanonical books.
The Apocrypha is not in the Bible for the following reasons;
1. Not one of the books is written in the Hebrew language, which was alone used by the inspired historians and poets of the Old Testament. All Apocryphal books are written in Greek, except one which is in latin.
2. None of the Apocryphal writers laid claim to inspiration
3. The Apocryphal books were never acknowledged as sacred scriptures by the Jews, custodians of the hebrew scriptures. In fact the Jewish people rejected and destroyed the Apocrypha after the overthrow of Jerusalem in 70 A.D.
4. The Apocrypha contains fabulous statements which not only contradict the 'canonical' scriptures but also themselves. e.g. Antiochus Epiphanes is made to die three different deaths in three different places.
5. The Apocrypha includes doctrines in variance with the Bible, such as prayers for the dead and sinless perfection.
6. It teaches immortal practices such as lying, suicide, assassination and magical incantations
7. No Apocryphal book is referred to in the New Testament, whereas the rest of the Old Testament is referred to hundreds of times.
8. Because of these and other reasons the Apocryphal books are only valuable as ancient documents illustrative of the manners, language, opinions and History of the East.
All of this information is easy enough to access. There is a good link here to some more opinion on the Apocrypha.
http://watch.pair.com/apocrypha.html
Hope this is helpful.
Stephen