When you are making corrections to your book it is easier if you start on the last page and work forward. The reason for this is that as you make changes to your manuscript on the computer everything after it will move. So if you start at the first page then as you work your way through the book it will be harder to find the corrections because the computer screen won’t look the same as the printed proof copy. By starting at the last page any change you make will effect the pages that you have already edited.
If you have pictures in your book, then after you have finished the corrections, start at the beginning and check to be sure that the pictures are still where you want them.