A workbook with many chess puzzles. There are two types of books on tactics, those that introduce the concepts followed by a some examples, and workbooks that contain numerous exercises. Chess masters Franco Masetti and Roberto Messa have done both: they explain the basic tactical ideas AND provide an enormous amount of exercises for each different theme. 1001 Chess Exercises for Beginners is a great first tactics book. It helps you in identifying weak spots in the position of your opponent, in recognizing patterns of combinations, and in visualizing tricks.