William Zinsser's book, On Writing Well is excellent. The book is based on the course that Zinsser taught at Yale University and focuses on writing non-fiction. Many of the basic lessons of writing are included - things like "after you have written a piece, go back and edit 50% of the words." It is more the way he reminds us of these lessons that make it a great read. (Geez, maybe that means it is written well.)

Fresh on the heels of reading OWW, I also picked up a copy of his How to Write a Memoir. The move wasn't motivated by a desire to write my memoir, but a desire to read more of his work. This too was a good read. Whether you write for a living, live for writing, or just dabble in the world of blogging - these are excellent tools.