I'm a vegetarian slowly moving into veganism. If you're interested in becoming vegan, this book is a good start. It provides excellent information on general nutrition, as well as details on vitamins and minerals to which vegans will want to pay close attention. It even includes a one-day meal plan for several different levels of caloric needs.
If you're a vegetarian or an omnivore wondering why anyone would become vegan, this is NOT the book you want. Melina and Davis, both registered dieticians, focus entirely on their specialty. There is no information about animal cruelty in the dairy and meat industries and no discussion of the environmental and social benefits of a vegan diet. There is also little mention of vegan concerns outside of diet, such as animal-derived products in toiletries. Except for the final "Vegan Diplomacy" chapter, the book is largely charts, graphs, and phrases like "docosahexaenoic acid." Despite this, "Becoming Vegan" is pleasantly readable.
Also, curiously, Melina and Davis choose to base their vegan eating pyramid on the USDA food pyramid, which has been heavily influenced by the meat and dairy lobby and is NOT the best guide to follow for optimal health. I suggest obtaining a copy of "Eat, Drink, and Be Healthy," the Harvard Medical School's guide to healthy eating, and using the special nutritional concerns covered in "Becoming Vegan" to adapt the omnivorous advice in that book to a vegan diet.
This is a worthwhile buy for anyone considering veganism. If you're already vegan, it is a great tool for ensuring your diet is nutritionally optimal and for dealing with detractors who doubt a vegan diet is adequate for human health.