The easy joke: 'Three Guineas' is why you never ask Virginia Woolf for money.
Three letters each ask for a donation for their cause: the first asks what can be done to prevent war, the second asks for funds to rebuild a woman's college, and the third asks for money to help secure jobs for the daughters of educated men. Woolf eventually answers all three, connecting the situations of all three together.
She makes a lot of good points here building off of and going far beyond 'A Room of One's Own' in the question of women's rights and the consequences of their being denied. The book not only answers the three letters, but is composed of ongoing "drafts" of letters to the individual factions as Woolf builds her argument and predicts the counter-arguments and objections her current letter might face. It's not conversational, but it is a dialogue. If that makes sense.
Her points are stronger and better argued here than in 'A Room of One's Own' but there isn't as strong of a narrative as Judith Shakespeare's to tie the book together and make it as readable. It's worth the effort, but at first I had a hard time getting involved with it.
The end-notes. I loved the end-notes. Sometimes they were just citations, others were extended ironic toeing-the-line digressions. I wish they had been footnotes though, in cases like this where the notes are something you ALWAYS want to check it was irritating to have to flip to the back of the book.
The book's focus on the rights of women (even if Woolf focuses only on the middle class) and the threat of war in the late 1930s makes this a great source of perspective for historians, literary types and feminists alike.