On Profwriting.com it is free to sign up as a Writer.
As a Writer you can upload your manuscripts for review and review other people's writing – in fact, we encourage you to do so. Here's how:

1. First you need to make an account as a Writer.
2. Then login with the details emailed to you.
3. To upload your work, click on the link to Upload a Manuscript. You are then presented with a simple form on which you can upload images (of yourself and your book jacket or a mood image), write a short description of your work and a longer plot synopsis,  and, of course, upload the manuscript files for others to download and read, ready for review.

Please watch the video below for a visual guide.

Submission form guidelines.

Images: Only three images allowed.
Summary: Short and sweet – can you describe your work in 12-25 words or less?
Description: Describe the plot, characters and narrative arc in 100 words or less.
Files: Maximum of four files allowed – perhaps your introduction and the first three chapters of your work, or the first four chapters. Once you have pressed the upload button you must enter a title for the file, which serves as its download link.