*correcting spelling mistakes and grammatical errors;
*ensuring that illustrations are correctly captioned and referred to in the text;
*producing or working to a style checklist to ensure consistency in hyphenation, capitalization, formatting of references, etc;
*sub-editing text written by a number of authors to ensure consistent house style;
*maintaining awareness of new words or phrases coming into popular usage with a view to ensuring they're appropriate for the readership;
*preparing preliminary pages for the title, contents and...