Robertson Davies said of Strunk & White that it teaches you to build the prose equivalent of a good sound chicken coop, but that many of us want to build something more elaborate. Which is true enough, but it is also wise to make sure you can build that chicken coop before undertaking anything more elaborate. I found S&W very helpful during my college years.Somerset Maugham's The Summing Up was also helpful to me in learning how to write. John Burke, one of my English teachers in college, pointed out once that in the chapters on writing in that book Maugham not only tells you about good writing, but is also at the same demonstrating it to you. I remain an admirer of Maugham's work.