I had the same problem too. (using the same book)
I found the problem on the book, it simplifies the steps by just asking us "Connect the outlets", but didn't specifically point out "File's Owner connect to nameField". Newbie like me will easily miss out this tiny details.
"
Connecting Outlets
.....Control-drag from
File's Owner to each of the text fields, and connect them to their corresponding outlets. ....." ~Apress
