Elaine Gould’s Behind Bars, The Definitive Guide to Music Notation is exactly what its title describes. It’s quickly become the indispensible reference for anyone who does music notation. The book speaks for itself and the reviews have been stocked with superlatives.
The title and book cover links will take you to Amazon’s site. Music students will be interested in knowing that if you buy directly from Faber Music you may qualify for a discount that’s not offered through third-party sellers. Depending on your location, that savings may be swallowed by shipping costs but it’s definitely worth investigating. Links to the discount forms are at the very bottom of Faber’s page.