Separate Editing from Publishing for pages

For your authors you need to set accounts with a “contributor” role. A contributor can writ content but can’t publish it. Then create a user for your editor and give him an “editor” role and he will be able to publish the content the authors had written.

The main problem you may run into is that contributors can not upload images. If you trust your authors to not use your site to upload some porn or other “evil” images then you can use one of the role editing plugins to give this permission either for all the contributors or specific users.