Over the years, I have received the question as to how many words or pages a book must equal for publishing consideration. Well, first, I'd like to say that the amount of words are irrelevant if the book is incomplete, so make sure you have written everything you want to say and have it edited by a professional. When it is finished, count up the words/pages and compare them to the chart located at the following link.
I found this chart created by Gloria T. Delamar from 1997 & 1999. This is a handy reference guide for anyone writing a book, screenplay or any of the projects listed.