It is always good to have reference books, and here are some of the ones I refer to for advice and information about writing and editing.

Writing Tools: 55 Essential Strategies for Every Writer – Roy Peter Clark

A very practical book with solid advice.

The Glamour of Grammar: A Guide to the Magic and Mystery of Practical English – Roy Peter Clark

A well organized reference book with helpful rules.

Help! for Writers: 210 Solutions to the Problems Every Writer Faces – Roy Peter Clark

A good book that has a lot of useful advice dealing with writing in general.

How to Write Short: Word Craft for Fast Times – Roy Peter Clark

An interesting book with useful advice for writing more succinctly.

The Art of X-ray Reading – Roy Peter Clark

A good book that explains strategies for writing, using excerpts from a number of famous books.