Over the past few weeks I have been getting a lot of requests to review books to see if they are in need of being edited. I have no issue with doing this, but I want to point out that any writing you do should be edited. Then review your edit, check it again, read it out loud and then edit it again. I know that seems like a lot, but the truth is writers and editors will never find everything that is wrong in the first pass review.
On a side note you should always have any work you plan to publish looked at by a professional. Having friends or family helping you is fine. However, mistakes in grammar, point of view, timing and time-lines are all something that an editor is trained to catch. You want people to buy your book, but the hard truth is they will not spend a dime on something that lacks attention to detail.