Well, you can't in default Alfresco. There simply is no feature for this. You would have to build it yourself as a customisation - and I am not aware of any community addon to add such a functionality.
On the other hand, do you know that you can activate a film strip view in the documentlist, which allows you to do a forwards/backwards navigation much like you want to have, while still having a preview of the document available, right there in the main document list view?
Yes I know about the film view, but what i want to have, is to be able to view the document and in the same time see it's properties (new properties that i created for a new document type). So that the user can see the file, and check if the extracted informations that are in properties are correct, and if it is pass to the next file without having to go back to the document list.