I'm not sure if this'll help any, but I'm REALLY into my Iberian ancestors so I got a book on the entire history of Spain. The beginning has some information on the Iberians and Celtiberians. The book is: "The Story of Spain" (The dramatic history of Europe's most fascinating country) By Mark R. Williams. It's not much, but I got to learn about my ancestors, so I'm pretty happy with it.