This is one book where the author spends 70 % of the time in telling "why" should you ever consider Lateral Thinking. In between this justifications there are few good ideas.
De Bone has given some interesting ideas that should be looked closely and practised by everyone, like the ones given below.
1. Look at the problem from a different angle (try reversing the problem)
2. Don't stop when one solution is found and keep looking for better ones for some more time
3. Try rearranging and jumping forward in solution seeking process even if the intermediate steps sounds illogical
4. Try to delay judgment so as to let new ideas grow
Place two irrelevant things in the mind for some time and analyze it, this might create an opportunity to look at the problem differently
5. Don't challenge an idea to find if it is right or wrong but look if it can add any insight at a different angle
6. Remove No and replace it with a new word (here he suggests using PO) that would challenge the statement and generate new ideas rather than rejecting an irrelevant one
7. Remove the cliché patterns my removing or looking deep into the labels
Looks more of a teacher's manual rather than a thought provoking book, might be of interest if you are planning to get new idea to teach your kid.