The title is quite an understatement. "Introduction" should be replaced with "everything you might possibly come across in your IT career". I remember it being a very good book, but very theory-focused and hard. Even if you just read it through for the explanations and exercises and skip over the heavy theorems and proofs, you'll know more than most professional IT workers in the field. If you are considering to buy it maybe borrow it from a library first, because it might be too difficult to go through alone if you are not used to the academic writing style.