The tactics book I recommend above all others!
I started assigning Chess School 1a to students circa 2007, and still recommend it in 2020.
There are 719 puzzles in this book, with an intended audience of absolute beginnners up to an approximate rating of 1000. I definitely recommend it as a first tactics book, and it can help a player for awhile.
The book starts with mate-in-1 positions where you are told what to mate with, followed by mate-in-1s where you aren’t told what to use. Next are puzzles where the object is to win a piece. Later come mate-in-2 puzzles, drawing combinations, endgame puzzles, and more.
I love the variety of the examples chosen and the gently increasing difficulty.
Directions are given at the top of each page in English, German, Russian, and Spanish. There are puzzles for white and for black, and the solutions are at the end of the book.
Chess School 1a will improve your pattern recognition and tactical skills. This book is not always easy to find, but it’s definitely worth it. I have ordered it from overseas in the past, but at the moment this isn’t necessary.
When you finish the book, be sure to move on to Chess School 1b!