Quite a lot of people did a review of this; I do not have much more to say in addition to what was said already.
The first Dresden Files book was entertaining enough for me to continue to the second one, but people say the real fun starts with the fourth book; I even went to sleep a little later to finish it. For now, it is typical hard-boiled crime novel (a broke PI, a mysterious beautiful woman, a good cop with the rest of them being jerks, etc.) with working magic. Think Buffy the Vampire Slayer for adults.
The rating is actually 3.5 stars, but I gave 4 considering the series' improvement mentioned above.