Now, I used to know quite a bit about wine "back in the day". I was a member of the international wine & food society, the Confrerie de la Chaine des Rotisseurs, and had actually run a "cadet" chapter of that for a while. However (needless to say), when I quit drinking, going to $300 a plate formal banquets where a good half of the costs were going to fine wines lost a lot of its appeal, and I started to pay less and less attention to wine.
Since I wasn't going to be personally doing a lot of research, I figured what I needed to get was a good, reasonably encyclopedic (in breadth, if not depth), book, and decided that picking up a copy of Ed McCarthy and Mary Ewing-Mulligan's Wine For Dummies was probably a useful way to go. I've not been a huge fan of the "For Dummies" books, but they do tend to at least give you a decent over-view of a subject (for instance, I once picked up "Visual Basic for Dummies" when I wanted to brush-up on some little-used programming skills).
Unfortunately, due to the nature of these books, it's a bit hard to offer up much of a subject-oriented critique. Wine For Dummies has an interesting structure, with the first three sections being targeted to the "Total Novice", the "Occasional Imbiber", and for those who have "Caught the Bug". The first of these deals with wine basics, how it's made, bottled, etc., how to deal with the wine section in a store, how to navigate a wine list in a restaurant, even how to open a bottle (OK, so this section was a bit "baby steps" for me). The second section dealt with the nature of wines and wine production, covering with how wines are produced, named, and regulated, tracked through France, the rest of Europe, the U.S., and various other wine-growing regions around the world, discussing the types, styles, etc. made in each location. The third section deals with buying, storing, tasting, selling, etc., etc, wine. There are also two other sections, one dealing with FAQs and one with various tables and data.
It took me nearly two years to get through this. When I bought it, I was simply trying to "freshen up" what I had previously known, and it ended up in the "reading stack" in one of the bathrooms here, to be chipped away at a few pages at a time when the sports section of the newspaper wasn't handy. This is not to say it's a difficult read, just my interest was never much in it. Today I saw that I was about 50 pages to the end, so tossed it in the briefcase to read while my kids were at Dojo this afternoon, where I managed to get it finally finished!
Frankly, this book would be super for a raw novice who wanted to educate themselves on the general subject of wine before spending a lot of money doing it the "usual way". My own approach to the book was hardly the best one for an unbiased opinion. The latest (4th, from 2006) edition of this book is currently available at retail, but the copy I have is the 1st edition (from 1995, so having some "antique" info!), and there are copies of this (or possibly subsequent editions) are available from the new/used vendors at Amazon for as little as a penny ... so you have a wide range of choices there. Again, if one doesn't know (or recall) much about wine, and wants an easy over-view, this could be a good place to start ... I certainly would have had to have gone to more in-depth references were I were to have progressed with bartending, but this did manage to at least "re-frame" what data I still had floating around my head about wine!