Develop User Manual for a web application

We have a web application which needs a user manual. once i choose a coder, i will send you login details to access our web application. You can work into that web application for a week or 10 days and ask any clarification to us. Then you need to create a user manual for our web application and deliver to us as a word document or in any other simpler format. The user manual must be written without grammatical mistakes. one or few errors will be adjustable. The web application consists of 50 pages, i need usermanual for all pages. For each page the user manual should be user friendly for all novice users and need to understand how to work in our web application by reading your manual. You need to insert necessary screen shots into manual. We plan to launch this web application in few months, so i need the user manual before that. We are happy to reply to any questions.