May I recommend you first check Nekomado shop for recent release of Shogi books in English.  The site also carries French and Chinese introductory books.

Also, you can check online used book network such as abebooks.com and even ebay for those books.

Introduction to Shogi

This is a pdf book written by Roger Hare, who hosted the oldest Shogi web site in English. The site archive exists in shogi.net which is still a good resource, but he put together those articles from the site and even more additional info into 200 page plus pdf book and keeping it up to date. The book is available from Eric's Shogi page for no cost.

Japanese Chess: The Game of Shogi by Trevor Leggett

The first one on the list is more of the historic book. This was the first Shogi book published in English by English gentleman, who lived in Japan and held very respective 4Dan certificate. It starts with the origin of Shogi and go all the way to explain nuance of Shogi play, also teaches how to read kifu. The book was originally published in 1966 but republished in 2009.

Shogi for Beginners (Mass Market Paperback) by John Fairbairn

This is a new book published in 2009. However, it does appear this is a reprint of "Shogi Japan's Game of Strategy" by the same author published in 1993.

Habu's Words by Yoshiharu Habu, Tony Hoskings, Yamato Takahash

Habu is perhaps one of the best overall player in today's Shogi world. He reviews several amatuar games and discuss various strategies and way of thinking. Though highly recommended, the book is out of print and hard to find.

Better Moves for Better Shogi by Aono Teruichi, John Fairbairn, and Sam Sloan Paperback- April 3, 2009

ex-A league player Aono talks about way of thinking in Shogi., rather than concentrating on each and every move. He shows novice's mistakes, explain why those are bad moves and move on to show better moves.

Ending Attack Techniques 200 by Takashi Kaneko

Original of this book is called "Ending attack techniques 186" and has been out of print for the longest time. Few years ago, Mr. Kaneko re-compiled the book material and re-published book with additional material. So instead of 186, now the book contains 200 examples. If you are serious about Shogi,get this book while you can.
Mr.Kaneko is a master of cataloging and methodically explaining of all those techniques. Highly recommended.
Unlike books that explains book openings, This book will not lose its value as long as Shogi rules stays the same.
The book is available through Nekomado online shop

Now there are several ebooks from amazon.co.jp. Altough I have not read any of them, all of them are receiving good ratings.

Comprehensive Shogi Guide in English  by Miles Yebisu

Shogi Primer: Japanese Chess Guide in English by Saigo Sato

Shogi Openings: Shogi Fundamentals, Volume 1 by Seigo Sato

Shogi Middlegame: Shogi Fundamentals, Volume 2 by Seigo Sato

Shogi Endgame: Shogi Fundamentals, Volume 3  by Seigo Sato

Tsume Shogi: 1-move checkmate 111 problems by Seigo Sato