The "Book of Jasher" also records the taking of of Enoch into Heaven 

Also see (Sira 44:16; 49:14)and Wisdom of Solomon 4:10-13.

http://apocrypha.org/

Who wrote the book of Enoch seeing as Enoch lived Long before the tower of babel. Why does the book of Enoch speak in past tense of things that were Long after Enoch? Just cause we see a statement both in the bible (Jude 14) and in the book of Enoch that is not grounds to qualify a source. Its not in the Jewish cannon of the Tanakh (OT). It seems to be a book with passed down traditions (stories/ legends) that may have been based off of known revelations within the culture.

"Book of Enoch" on giants http://nazarenespace.com/profiles/blogs/the-five-satans-in-the-book-of-enoch ;