Don't let the review below mislead you into to thinking that this is a piece of new-age fluff. Though neo-pagans may also get something out of it, "A Dictionary of English Folkore" is a work of serious scholarship and eruditon, compiled by two internationally recognized folklore scholars and published by Oxford University Press. As such, it is best compared to other reference guides published by academic presses (e.g. "The Oxford Dictionary of Saints", "The Concise Dictionary of American History", "The Norton Dictionary of French Literature", etc.), rather than to books on how to perform Wiccan sex magic.
Essentially, this is an alphabetical dictionary of English (not British, just English) folklore. The editors use a fairly broad definition of folklore and the 1000+ entries deal with nursery rhymes, fairy tales, folktales and legends, superstitions, holidays, customs, and even folk medicine and folk music and dancing. Topics discussed include: Mother Goose, Robin Hood, wassailing, the tooth fairy, Michaelmas, splitting wishbones, kissing under the mistletoe, and Morris dancing. The folkloric origins of many colloquialisms and other turns of speech (i.e. why is a ne'er-do-well refered to as "the black sheep of the family") are discussed, and there are even entries for a a few modern urban legends as well.
The entries are arranged alphabetically rather than thematically (it is a 'dictionary' after all) and tend to be fairly brief (a few sentences to one paragaph long). They do, however, have cross-references to related entries and come with citations so that those seeking more detailed information about a particular item can go find a source that treats it at greater length.
This isn't necessarily a book that everyone needs, but it is an *outstanding* reference guide and will be very useful to those interested in English culture, literature, and history. And frankly, even folks who don't really need a reference guide to English folkore will probably still find this a lot of fun to browse though. (The short entries actually make it great for casual 'bathroom reading' as it were). I don't give out five-star reviews lightly, but a well-researched, well-presented reference work like this deserves it.