Hard for me to recommend books now with the internet as a resource.
Any source that gives a broad outline of topics that needs to be learned is valuable...I recommend you take that outline and scour the net for reputable sources of info on the subject.
With a book...you spend a lot of time reading one person's opinion of what the right or several possible paths are the best solutions or choices or whatever the question pertains to. With the net you can cover a lot of territory quickly and not only focus on what the general topics in that area cover...but you can review ongoing questions of boaters pertaining to that specific topic and review a bunch of opinions that with a bit of evaluation can send you off in directions to further the answer to that question. Forums like this are good for that. Lets say a controversial topic like anchoring or how many engines. I don't think I ever read a single book that adequately covered those topics. Because in order to do that, they had to cover all boats, all styles of cruising in all areas of cruising.... the new you can ask a question in a forum and in a day or two have a bunch of opinions that may be much closer to your probable boat, your probable cruising area and style...etc..etc. You can arrow your search of detailed info that will be way more valuable than from some broad stroke book.
Some exceptions are tech books on such topics as electrical, engines & fuel systems, somewhat plumbing.... probably more books/topics but in reality I feel the net will still be a much quicker and better review of nearly any subject. Each new search will lead to new categories you need to ad to that outline of topics you need to know before serious, distance cruising. Buying a boat, daytripping around the harbors or a few mile cruise here and there doesn't need much more than a good dockmate to point you in the right direction. Loops, Bahamas, offshore stuff and beyond is a different story. Those need a bunch of building blocks of study and hands on practice.
One thing that is absolute... rarely believe almost any post or poster without a lot of research into what they offer in a couple paragraph post. No matter their experience, reputation, reported experience an on and on.... there is always more to the story. Embrace that as that is where you will see dated info, personal opinion vs facts, info that doesn't apply to you..... I am sure you get my drift.
