This book starts off with an interesting explanation on how habits are "chunked" behaviour that resides in the brain's basal ganglia.
The thing about habits is that they can be either good or bad. The trick is to develop good habits before you have a chance of developing bad habits.
If you are trying to change a bad habit, then you will need to do this by developing a bunch of tiny good habits then will result in improved behavior.
All in all, a very good book.