As I understand it the bible is considered a collection of books. So it could hardly be considered an average book.
Depending how well you want to know the bible
Treat each book within the bible as a book. preview 5-8 minutes PR 1 page per sec print size doesn't matter still 1 pg per sec. Activate in 15 to 30 minute sessions depends on how much you want to know. If you want to go even deeper you could do it chapter by chapter.
On the whole average book would be 300-400 pages and take the average reader approximately 10 hours to read.
Books of a technical nature can exceed 800 pages therefore it is usually recommended to handle them chapter by chapter for activation and comprehension. The better you want to know the subject the more you want to activate. So chunking into smaller sections helps
Technical books normally take longer to read, usually because each chapter may take repeated reading when regular reading to comprehend the subject suffiently. This is the factor usually overlooked when comparing the Photoreading method to speed reading or other methods. 
My conclusion of an average book... taking all the books in my library and noticing the number of pages each has... average 350 pages
Hope this helps
Alex
