YourDictionary.com offers this recommended list of grammar resources for those wishing to polish up on your grammar, increase your vocabulary and brush up on your writing skills.
No matter where you are in life, good grammar is always an important skill to have to help you communicate successfully and clearly with the rest of the world. Whether you're a student, teacher, job seeker or professional good grammar is essential for making the correct impression on the people you communicate with everyday. Good grammar is a direct indication of your competence for whatever goal you are trying to reach.
Just as good grammar is important, a large vocabulary is another necessity for being able to express yourself correctly.
Whether you're working on increasing your vocabulary, your understanding of the English language or need help with good writing style the books below can all help. All of them are good desktop references to have on hand to increase your English grammar, vocabulary and writing skills.