I have spent many hours of my life over the past five or so years searching for every book containing any sort of valuable information on sports handicapping. I quickly found that there are very few books with any kind of value that were written specifically about sports handicapping, which I define as the process of making one's own number or price on a game. Coming from a poker background, I was shocked by this - there are dozens of excellent poker books that no one would question have made poker games worse. Perhaps the reason for the lack of good sports handicapping books is that top sports bettors make far more money than top poker players, meaning there is less incentive for them to give away their methods in a book.
After reading the few good handicapping books, I moved on to read several books that were about sports betting, but not necessarily about handicapping, as well as books on horse racing and finance. While there is not much on sports handicapping in any of these books, there are plenty of techniques described that can be valuable to the aspiring handicapper.
I am not going to give any sort of number score on any of these reviews; while some of these books are better than others, in my opinion if you are serious about sports betting, all of these books are worth reading for various reasons. Also I have no affiliate relationship with Amazon or any of the writers of these books, although that would be an incredibly sick angle to push affiliate links to a book that contained losing handicapping information and affiliate links to sportsbooks.
Sports Handicapping
Sharp Sports Betting - A solid book designed for beginning to intermediate sports bettors. There is a great deal of material around how to calculate expected value, basic handicapping methods, and of course, the famous Wong teasers. There isn't much in here that will help you handicap games, but at least it teaches the underlying math behind getting an edge. Some of the information in the book on the NFL is a little outdated, but overall, a classic book.
Conquering Risk - A lot of good content on the fundamentals of sports betting markets and how long-term winners win. The book's emphasis on targeting props and good lines is sound for the overwhelming majority of sports bettors. This is also probably the only book out there that actually goes through the process of building a sports betting predictive model that would have had at least some chance of winning at the time the book was written. It is worth buying for that reason alone. The only issue I have with this book is that half of it is devoted to stocks. While there is nothing wrong with the stocks section, I think most people who would buy this book are unlikely to have much of an interest in stocks.
Sharper - Most of this book is not really about sports handicapping, so much as the overall philosophy and process required to beat sports betting. This sort of content is unique in the gambling literature and is perhaps more valuable to most bettors in the long run. The book is geared more towards beginning sports bettors but there is plenty of good handicapping content towards the end of the book for professionals as well.
Horse Handicapping
Picking Winners - Probably the best known book in the history of handicapping and a very entertaining read. The key takeaway from this book is the importance of adjusting statistics for context, which has immense value beyond just horse betting. The other two books in this series by Beyer are also worth reading, for entertainment if nothing else.
Precision: Statistical and Mathematical Methods in Horse Racing - A disclaimer, this book is $30 on Kindle and the author's first language is Chinese. As gamblers looking for information relevant to making money, neither of these should usually be big issues. Unfortunately, the language is a big issue in this book, because parts of this book use statistical and horse racing terminology that has been directly translated from Chinese into English. Much of this terminology does not line up with what native English speakers use, making parts of the book difficult to understand.
Translation issues aside, from the perspective of someone who wants to learn how to win, this may be most valuable book ever written on handicapping, horses or otherwise. Although the specific models used tend to be more applicable to horse handicapping, the statistical methods presented are sound and are very similar to the methods used by top professional sports bettors. Perhaps more useful are the author's discussions around his handicapping process, the workings of syndicates, and market psychology. Mandatory reading for all aspiring professional gamblers.
Finance / Other
Reminisces of a Stock Operator (free pdf link) - Given this is a nearly 100 year old book about stocks, one would not think this book would contain much relevant information about sports handicapping. However, the sports betting market today is very similar to the early 20th century stock market in that it is often driven by inside information, momentum/steam bettors, tip followers, and other dumb money. From this standpoint the book is very valuable as it gives great advice on what one should look out for in this type of market. Handicapping is not just about building models and pricing games; there is plenty of information that can be gleaned from line moves even today. Equally valuable is the chance to understand the mindset of a serious professional gambler and how he handled the ups and downs of gambling on stocks.
Sports-Specific Books
The Book: Playing the Percentages in Baseball - Easily the best book on sabermetrics, parts of this book seem to be written specifically with baseball handicapping in mind, which makes sense, since one of the authors is one of the most successful baseball bettors ever. From a handicapping perspective, the thought process behind answering the book's questions on baseball strategy is more valuable than the answers themselves.
Basketball on Paper - The fundamental tome that spawned basketball analytics. The concepts presented in this book are used in some form by all top basketball handicappers today. There may be better books out there nowadays on basketball analytics but in my opinion this is all one needs to know to get started.
Every Shot Counts - Really the only golf analytics book out there, but unfortunately most of the book is devoted towards using analytics to improve your golf play. However, if you want to get into betting golf, there is some great material in here that can be used from a betting perspective (although this golf analytics blog is even better).
I probably missed some fine titles here, especially some of the older print-only books I have not read, but this should be a good start. As for math/statistics books, which everyone definitely should read, I unfortunately don't have any to recommend. Most textbooks are brutally awful for those just looking to learn the basics and you can probably do better with random Google searches.