Whilst thousands of chess books have been written for players over 2200, especially about the openings, there are still relatively few good ones for players at lower levels. Go down to to post beginner level and there’s really very little.
Bobby Fischer Teaches Chess is one of the happy exceptions. Although (or maybe because) Bobby Fischer did not write it the content is spot on, showing simple tactical ideas and mating patterns. You get immediate feedback (the answers are always overleaf) and you can read it without setting the positions up on a board. The title was derived from the use of Fischer’s games in the positions, and some of the text makes it sound like Fischer was writing it. Needless to say Fischer was not amused!
This was the first chess book I went through with my son (now 9) and he now knows a thing or two about chess to the extent that he’s probably the number two player in his school. I used a bad extrinsic motivator to get him to go through it by paying him 5p for each position he solved. That may sound expensive (it will cost you £13 or so on top of the cost of the book) but in terms of improving a child’s playing strength I figure it’s a lot more cost effective than hiring a GM to teach them, and that includes me!