Some of Ryle's followers have extended his ideas to the point of distortion, and would have us believe that mind and consciousness actually do not exist. Don't let such behaviorist extremism put you off. Ryle's feet were always more firmly on the ground. He defines the concept of mind, not invalidates it.
He has a lively, readable style (of how many philosophers can you say that?) and although a lot of his ideas do not have the novelty that they would have had half a century ago, this is still the best book with which to begin an investigation of the nature of mind and consciousness.
Ryle's book is chauk full of arguments, long ones, short ones, simple ones, subtle ones, with a particular predominance of infinite regresses. Even if you think, as I do, that many of these arguments are misguided, you will still be put through a variety of mental gymnastics as you try to diagnose the various faults they hide.
One note of caution, because many of Ryle's arguments are of the ordinary language variety, his linguistic distance from us (the book is over 50 years old, and British to boot) does hinder understanding. It was not always clear to me whether Ryle was misusing a word, or whether its use is different for us than it was for him.