Out of millions and millions of books on education... which, of course, I never read, I picked up this short list of books I read and found useful.
The only education books that kids actually STOLE from me are from the "Core knowledge series" edited by E. D. Hirsch Jr and range from the kindergartner to sixth grader under the title "What your (for instance fourth grader) needs to know". Each book covers language, math, geography, art, natural sciences. It is very nice reading, it is uplifting and adults might learn a thing or two. It is not practical (no tips on teaching, no exercise), but at least it tells you where the kid should be. Do not assume that if you give it to kids, they will just love it: you got to pick up a subject at a time and go over it with them.
The seven habits of highly effective teens by Sean Covey. The book is simple, well informed, healthy, fun to read, useful even for parents. I am not the only person to think so: the book got millions of copies sold.
You cannot beat Princeton on the preparation to the SAT. The book is fantastic, and most of the usual mistakes that kids usually do are explained. I like it so much, I constantly use it when I volunteer with kids that are still years away from high school: the basics are well covered, so you can benefit from it at any age. The last versions now come with a DVD.
Thomas Foster, How to Read Literature like a Professor. You read the first chapter and your mind goes "AAH!" Now I know how to read this (and also how to teach this).
David Lazear is an author who irritates me no end, but by lack of a better book, I have to cite Eight ways of teaching (the artistry of teaching with multiple intelligences). If you are a teacher/parent wanting to ask more of the brain of kids, this is useful, do not mind me.
Tom Stafford and Matt Webb, Mind hacks, Tips and tools for using your brain. Finally a useful book. I like it much better than the well known Owner's Manual for the brain, by Pierce Howard which is OK, but mixes up science and common sense in variable proportions, making you believe this is the edge.
You also need a very thick dictionary, such as the Oxford American College Dictionary I wish it would be much much bigger, but it is the best I could find. Avoid Webster. Do not buy anything concise or pocket: it looks like it makes sense, but it is useless.
Splurge on a Reverse dictionary ***: instead of looking for synonyms, these dictionaries look for ideas. It is a fabulous help.
Buy anything from Amazon here, it does not cost you more, and it helps me.