This next review is long overdue - as some of the first books I ever bought for myself once I finally decided to take the plunge into Celtic Reconstructionism, they've been instrumental to my path and my research, and their value cannot be overstated.
The Silver Bough: Volume I-IV
F. Marian McNeill
Coming in at four volumes, the full set for the series may set you back a pretty penny if you indulge yourself in one go, but I can tell you straight away that these books are well worth it. I'd originally intended to review them all separately, on their own merits, but in the end I decided that was pointless seeing as I'm not sure they can be fully appreciated without reading each book, and many of their strengths and weakness are the same or very similar. I figured I'd probably just end up repeating myself.
First of all, I'll give an idea of what each volume covers:
The Silver Bough Volume I: Scottish Folk-Lore and Folk-Belief
Here we have an introduction to various aspects of folklore, from witchcraft and fairies, to different types of charms and folk practices. Of all the introductory tomes to the subject, I think this is the most accessible and strikes the right balance between hitting all the right bases without overloading the reader.
The Silver Bough Volume II: A Calendar of Scottish National Festivals Candlemas to Harvest Home
Covering Candlemas, Easter, Bealltainn, Lúnastal and the harvest festivals including Michaelmas, this is probably the best place to start if you want to find out anything about these festivals. Again, it's accessible and detailed, but won't overload. For some subjects - like Bealltainn - various different aspects of it are covered in several chapters, but for the most part this is the sort of book you can dip into as and when you get to each particular time of year to get an understanding of what the festivals are about, and for ideas of what you can do.
The Silver Bough Volume III: A Calendar of Scottish National Festivals Hallowe'en to Yule
Covering a slightly shorter period of the year, but with good reason because there's a lot to pack in. Chapters include covering Samhainn, Christmas, Yule, Hogmanay, and Handsel Monday. Much of what you'll find for Samhainn/Hallowe'en is also covered - with more additional details - in McNeill's standalone book, Hallowe'en: Its Origin Rites and Ceremonies in the Scottish Tradition.
The Silver Bough Volume IV: The Local Festivals of Scotland
Covering the different local festivals, grouped loosely by the time of year (although there's some need for a bit of backwards and forwards here). Of the four volumes, this one is probably of least immediate value and relevance to the beginner, but it gives good additional details for when you want to get stuck in a bit further, or are looking for customs that might relate to somewhere you have heritage from.
The value of these books - and the love I have for this author - cannot be overstated. Although I'd unreservedly recommend the whole set to anyone, however, that doesn't mean that they're not without their problems...
The first volume was published in 1957, with subsequent volumes coming out every couple of years thereafter. This means that not everything is necessarily as up to date as you might hope, and some of the interpretations given by McNeill aren't necessarily solid. I tend to be more forgiving of things like that in older books such as these, but they need commenting on all the same - McNeill's frequent mention of druids, and linking customs with 'ancient druid practices' need to be ignored, for example, because there's simply no evidence to support what she's saying there.
Likewise, because much of McNeill's research is based upon older books, it helps to know what you're dealing with there. She goes along with Fraser and his The Golden Bough sometimes, and for the Cailleach, for example, she draws upon MacKenzie's work. It has to be said that he's not necessarily the most reliable source for that kind of thing even if he is interesting. It helps to be a little circumspect there.
References are given throughout the volumes but in trying to follow up on some things, McNeill hasn't been as thorough as I would have liked. Having familiarised myself with a lot of the stuff she's drawn her research from I can see where bits have come from now, but it does cause a headache or two if you don't know to start with. What she does reference, however, is sound - she doesn't try to fudge anything with giving references that don't really follow what she's saying, so over all you'll find she's quite reliable.
Because of the cost involved in getting hold of all four volumes - not outrageous, but not necessarily within everyone's means - I've tried to find alternatives. The Scottish volumes of British Calendar Customs are a good substitute, but unless you can find them from the library you probably won't have much luck buying them and I would say they're probably not as readable as McNeill anyway. Sheila Livingstone's Scottish Customs, and Scottish Festivals, both draw heavily from McNeill, are cheaper and less detailed, and might do well for someone who's a little daunted by the prospect of getting stuck into four volumes right away. I reviewed those as well, and found them to be a little problemmatic, though, so my recommendation there comes with a bit of a qualifier.
The Silver Bough is by no means the only thing you'll ever need to read, but it does give a fantastic start, I think. Along with Ronald Black's The Gaelic Otherworld, I would recommend the first three volumes (at the least) as must-haves for the beginner.