Who's Who in Classical Mythology is an indispensable guide to all the Greek and Roman mythological characters, from major deities such as Athena and Bacchus, to the lesser-known wood nymphs and centaurs. Also included, of course, are the heroic mortals, figures such as Jason, Aeneas, Helen, Achilles, and Odysseus, all brought to life in a fascinating series of portraits drawn from a wide variety of ancient literary sources. Each entry offers a small window into a timeless mythological world, one filled with epic battles, bizarre metamorphoses, and all sorts of hideous and fantastic monsters. The perfect book for casual browsers and folklore enthusiasts alike, Who's Who in Classical Mythology offers a rich and readable guide to some of the greatest stories ever told.
Michael Grant was an English classisist, numismatist, and author of numerous popular books on ancient history. His 1956 translation of Tacitus’s Annals of Imperial Rome remains a standard of the work. He once described himself as "one of the very few freelances in the field of ancient history: a rare phenomenon". As a popularizer, his hallmarks were his prolific output and his unwillingness to oversimplify or talk down to his readership.
This is without a doubt my favorite go-to reference for information on the gods and mortals. Good detail, very informative, and lists alternative names as well.