Susan Harrington Although my husband reads them all, this is the first of Kellerman's Alex Delaware series I have read. I had no difficulty following the story or characters. It was a quick enjoyable read!
Cheryl You certainly don't have to, I've read the books out of order, but the more of them you read, the better you understand the characters.
Dawn Livingston Well, it's best to start at the beginning to get the bits and pieces of character development. However, I think there are about 29 books in the series now so... You could start anywhere and be alright, you won't be lost. However, chances are your local library has a copy of the first of the series. Try that and if you like it, then dive in anywhere you like.
Traci Haley I implore you to start at the beginning. While I don't think you'd necessarily be lost at starting at his recent ones, you *will* miss plenty of character development, which is what make the books worth reading. Also, in my opinion, the more recent books are a bit on the "blah" side compared to when the series was fresh.