The series gets better, can't remember if the first book does.
The first book was written as a project for a writing class he was taking - as the author himself said:
"When I finally got tired of arguing with her and decided to write a novel as if I was some kind of formulaic, genre writing drone, just to prove to her how awful it would be, I wrote the first book of the Dresden Files."
https://en.wikipedia.org/wiki/The_Dresden_Files
While the first book wasn't great, it wasn't awful either, however the author really hits his stride as the series goes on and the books, and writing, gets better and better. IMO anyway. I thoroughly enjoyed the series