I think this thread should be moved to 'General Chess' as the question posed by Kafka covers all 1.d4 sub-Forums. However, it is up to the moderator to determine whether this would be an appropriate action. 

I will offer the following brief suggestions for now:

<1400: King's Indian or Modern Benoni
<1700: Queen's Gambit Declined or Slav
<2000: Nimzo/QID/Catalan/Cox's book or Benko

Note: In order to provide more precise, constructive advice, I would need more information on Kafka's style/rating/current openings.

Well, I would pick an opening, before picking a book, rather than the other way around.   

You can get pretty much any repertoire book that strikes your fancy and then supplement it with Cox's Dealing with d4 Deviations or Dembo's Anti-King's Indian book.

That said, Rizzitano's book on the Queen's Gambit Accepted is a good, all-around solution.