This book was really essential when I was going through school. It’s a classic in teaching students on how to write well. Just came across it this morning on Amazon and saw it was… free on the Kindle.
‘The Elements of Style’ (1918), by William Strunk, Jr., is an American English writing style guide. It is the best-known, most influential prescriptive treatment of English grammar and usage, and often is required reading and usage in U.S. high school and university composition classes. This edition of ‘The Elements of Style’ details eight elementary rules of usage, ten elementary principles of composition, “a few matters of form”, and a list of commonly misused words and expressions.

Amazon product: The Elements of Style, Fourth Edition
Customer Reviews:
5+ stars and 9/10 hearts. This book is excellent and every single writer—whether you are a professional author or simply a high-school student—needs it. Simple, clear, witty, wise (and really very pretty as a printed book or an ebook—crisp and clean in style.) I recommend it to anyone 13+ for understanding. There is a mention of a sperm bank and one curse word, but in each case they are in example sentences and can be whitened out easily. There’s also sentence quoted from another writer as an example that mentions wine, but only in passing. The rules are excellent reminders; there are plenty of help for words we all get confused between; the last chapter is beautiful and amazing; and did I mention how humorous it was? This is one of those books that should be read at least twice a year, and that I just love to read. It’s also one that can be finished and begun instantly. Highly, highly recommended. | A Favourite Quote: “Write in a way that comes easily and naturally to you, using words and phrases that come readily to hand. But do not assume that because you have acted naturally your product is without flaw. The use of language begins with imitation. The infant imitates the sounds made by its parents; the child imitates first the spoken language, then the stuff of books. The imitative life continues long after the writer is secure in the language, for it is almost impossible to avoid imitating what one admires. Never imitate consciously, but do not worry about being an imitator; take pains instead to admire what is good. Then when you write in a way that comes naturally, you will echo the halloos that bear repeating.” | A Favourite Humorous Quote: “Flammable. An oddity, chiefly useful in saving lives. The common word meaning ‘combustible’ is inflammable. But some people are thrown off by the in-and think inflammable means ‘not combustible.’ For this reason, trucks carrying gasoline or explosives are now marked FLAMMABLE. Unless you are operating such a truck and hence are concerned with the safety of children and illiterates, use inflammable.”