Scottish Customs and Scottish Festivals
These are two separate books by the same author, but seeing as they basically go hand in hand, I might as well lump them together.
I saw them recommended on a college book list somewhere so thought I'd give them a go. I wasn't really expecting much in the way of new information, so when they arrived any high hopes I might have had weren't exactly dashed. Livingstone draws heavily on McNeill's The Silver Bough as a source, so for the most part it's a rehashing of that work. This is good and bad in a way, because they're shorter volumes and there's only two of them. In that sense, it will cost a lot less to buy them than all four volumes of McNeill's work and being shorter, there's less detail to overwhelm someone who's new to the subject, if they're looking for a basic nuts and bolts sort of introduction. They're much easier to get hold of than McNeill's work, and therefore much cheaper as well.
That said, I did find some elements to be problematical, mainly Livingstone's emphasis on the customs and festivals relating back to the Druids. It was alllllll about the druids, when really there's nothing concrete to prove such a link; McNeill does this too, to be fair, and it's clear that this is where Livingstone's drawing her information from. Being a relatively recent book, though, I would have expected it to reflect a more modern attitude to the issue. It's easy to read around, but I found it very (and probably unreasonably) grating.
The Scottish Customs book is perhaps a little more useful than the Scottish Festivals book because it offers a little more in the way of detail, and is less reliant on McNeill. It splits the customs into different headings like Birth, Death, Marriage and so on, and then details the customs under separate sub-headings, making it good for flicking through and quick reference. It covers pretty much the same stuff as Margaret Bennett's Scottish Customs from Cradle to the Grave (which is the one I'd recommend for quality and quantity of information), but Livingstone's book is less academic and therefore a little more readable, in some respects, because it takes a more conversational, less analytical tone.
My first port of call would still be The Silver Bough, but as I said, the advantage of Livingstone's books are that they're more accessible and easily available. I'd recommend them with the caveat to be a little more circumspect about the druid issue than Livingstone is, for starters.