Since discovering the wealth of go books in Korean, available from Het Paard, or by importing directly, I have become a frequent reader and follower of these books.
It has even gone so far as for me to learn some basic Korean to be able to read these books, and chat with the friends I will meet in Korea when I go there to buy more books.
Here, I will tell you why you should get Korean go books, which ones you should get, and why you don't have to learn (all that much) Korean to be able to "read" them.
The basic reason is very simple, so I will state it as a fact:
Fact 1: Korean go books are better than their English counterparts (in my highly subjective opinion). Our next fact will only contribute slightly
Fact 2: The author has read or glanced through most English language go books.
The only reason that you should NOT get Korean go books is summarized in the last fact:
Fact 3: A go book in Korean will (usually) teach the reader each thing only once.
So, for most text-books, you can not use them for learning by repetition, but only as a source of ideas.
In a few days, weeks, months or years, depending on your frequency of collecting, your bookshelf is full of Korean books. But one little problem remains: Which books should you buy?
The answer here is not so hard either, because the Hankuk Kiwon (Korean Baduk Associasion) has released a wonderful series of 23 volumes(1 still unpublished) covering every aspect of Baduk. Beware though, the books are all cover topics that stronger players will benefit from. This is not saying that they are useless to intermediate players.
If you like, you may see the following as a complement to the excellent reviews by Robert Jasiek (who, amazingly enough, draws the conclusion that the text in most Korean books does not require reading to understand the book, although he doesn't know any Korean).
1. Maeg Dictionary: (ISBN: 89-7990-002-3) A tesuji book, not comprehensive, but difficult even for the dan player. Most patterns are solvable within a minute or so, but although there is nothing really hard in the book, it is an excellent compilation of commonly occuring patterns.
2+3. Dictionary of jungsuk (현대정석): (ISBN: vol 3: 89-7990-025-2) Part of volume 2 is translated to English as Jungsuk in Our Time. The star point joseki covered in the 3rd volume are very interesting as well.
4. Master of Haengma: (ISBN: 89-7990-014-7) A book that belongs in every go players library. Haengma, the concept of making good shape on the whole board, is poorly understood also by dan players, but even a 10k has a lot to benefit from reading this book.
On making light and flexible shape, on avoiding korigatachi and in general, on looking at the whole board. The one problem with this book is that it contains few "standard" patterns, something that Dictionary of Haengma (not discussed here yet) and Dictionary of Basic Shapes (also avoided here) does in excess.
5 Choice of jungsuk (정석선택의 기로): (ISBN: 89-7990-094-5) A nice book, that for most people will be more interesting than the 2 previous volumes on joseki. Tries to teach how to choose the right joseki, in various positions. In a sense, this book is much like "The great joseki debates", but with somewhat drier text, and lots more examples.
As a foot-note, "The great joseki debates" is one of my favorite English go books, ranked right up there with "Lessons in the fundamentals" and "Attack and defense"
6 Modern poseok: A difficult book, that will mostly show the poseok from pro games and discuss some scope for variations, and pitfalls in the various fuseki patterns. The strategic level seems very high to me, and while I could imagine playing some of the fuseki, the discussion is usually way over my low-to-intermediate-dan-level head.
7 First 30 moves in the opening: As far as I can tell right now, there is absolutely no reason to get this book(but I do have it). It has some examples from pro games, but it seems they always end right when it's getting interesting, sometimes right when a big fight is going to start. A strange book!
8+9 Practical life and death problems: This book is very nice, but sometimes very frustrating if you are used to regular L&D books. The book contains a number of patterns, in problem format, stating white or black to play. But, and this is a big but, the problems are of the kind "black to play and find the best move". It may turn out that with the best move, black can not live, but perhaps leave certain aji on the outside.
Anyway, as a conclusion, this is a must-buy for any serious low-kyus or dan players. The 2 books together cover 600+ problems, including lots of commonly occuring carpenter squares, L shapes, and side invasion patterns.
11. Judgement: Contains examples from pro games, with examples of how to count the game. Usually, each game is covered in 3 stages. Usually, the phases could be seen as 3 phases of wrapping the game up for the player who is ahead at move 70 or so.
And this is the problem with the book. One player(the strong pro who is ahead) turns out to be 5 points ahead 70 moves into the game, and decides to wrap the game up. So he plays only "simple territorial moves", to avoid giving the other player a chance. A lot of the diagrams and commentary is like this, and is very difficult for a not-too-strong amateur to follow.
The following three books, by Lee Chang-ho and Yu Chang-hyuk respectively, are absolutely excellent. They are probably the two subjects that benefit the most from the exposition of only presenting a number of well-organized examples.
12+13. Invasion and reduction (침투 와 삭감): (ISBNs 89-7990-043-0, 89-7990-070-8) My favorite source of ideas for making interesting moves over the last few months. Presents a number of examples of interesting invasions in difficult positions, always taken from pro games.
Beware: Over-all, the two books show around 100 examples. As a first estimate, 20 of these examples are "standard" moves, that a 5k or 10k could recognize from their games, or from English language go books. Most of the examples are "pro moves", found specifically when the standard move doesn't work.
As a first example from the book, look at /Problem 1.
15 Attacking Know-How (공격 노하우): (ISBN 89-7990-075-9) On every possible way to attack a group, with examples only from pro games, and lots of well-chosen variations. 50+ positions discussed, over almost 300 pages. Just like volume 12 and 13, an excellent source of ideas and inspiration for your games. Mostly dan-level!
18 Soksu clinic: (ISBN: ....) Soksu means bad move, in the sense that it is aji-keshi, inefficient, or otherwise not the best move. So this book will try to remove that kind of moves from your game, and teach you to play suji.
Examples include playing atari to remove aji, pushing from behind, pushing the opponent on the 4th line.
Toward the end, a lot of the examples are taken from pro games, but sadly enough, the diagrams are not as well commented, so you will need either to trust your diagram reading skills to be at least a few dan, or to know quite a bit of Korean.
22+23 Endgame Techniques: The first disappointment in the series is these two last books. Spending ten pages going through some principles for the endgame, then the other 400 or more on end-game tesuji, one pattern per every two pages.
The level is mostly low kyu to dan level, but the book just can't compare in interest level with most of the other books in the series. The endgame, by Davies is still the best general book I have seen on the endgame.
: Velobici: I dont understand this. Why is once better. We learn by repetition. Teaching the reader each thing only once is the opposite of the way we learn which is seeing a new idea in several contexts, trying to use it, failing, understanding through why the attempt failed thereby gaining additional knowledge of the idea in the proper context, till finally we can employ the new idea correctly.
minismurf: This was mentioned as the one reason NOT to get Korean go books, as I now emphasised above. For a 10k, it may be purely destructive to see off-beat moves, giving the opponent territory on the fifth line for a giant moyo, say. But it may also be a great source of ideas. We should not dismiss that the Koreans are by far the strongest players in the world.
Charles South Korea would have more pros in the world top ten than any other country, I suppose. In order to understand more, one has to understand various effects: particularly opening research and 'secret weapons'; and the timit limits. Of course their training programs leave all others in the shade, too.
Juan: I have been unable to find "Master of Haengma" on any of the online bookstores. Just out of curiosity, where can you purchase (in the US) this book? Thanks!
Anon: yclwaller.com has copies, but they ship from Korea. Possibly, also http://www.aladdin.co.kr has copies, if you can read Korean (I believe they have an office in the US also).
Bob McGuigan: The yclwaller address goes to a web page which says that Waller's go book business is closed indefinitely. The U.S. address for Aladdin sends you to the same page as the Korean one.
Juan: So no sources in the US, or at least in English? As Bob wrote, Waller's is out of business, and Aladdin's site is only in Korean. Thanks!
Bob: One possibility is to find someone who reads Korean to help you use the Aladdin site. If you have the ISBN number it should be possible to order the book.
wetnose: I had been considering doing something like this...but how many people would be willing to buy (in the US)? It's a problem of logistics...Velirun, it'd be cool to work with ya ^^
UPDATE: I was working on translated books, but have no capital, so that's kinda dead. 2nd UPDATE: starting up in summer; suggestions as to books (or one very good book)?
Velirun: I've gotten a fair number of orders so far - enough to justify keeping the shop open, and developing my site a bit more.
wetnose: The 2nd ISBN for each book is the same so maybe it's a ISBN for the whole set.
: Adrian Ghioc: That is a very interesting approach. In the real games, you don't know the outcome (like in the regular L&D problems), you only know whose turn is and that's all - you have to play the best move. Such unusual problems should become the regular type of problems, that's training for real life where you don't know the outcome in advance!