4-6 weeks before your cruise you get your luggage tags. And a booklet summarizing your cruise. The only thing you need to bring with you out of that packet are the luggage tags and even those are optional.
You get your "cruise documents" when you do your online check in. The signature page is all you really need (well that and your photo ID, BC and/or Passport along with the CC you put into the system to pay for your onboard "stuff").