I usually try to put together a basket that includes things that I loved as a new parent. I usually include a little newborn sack bundler, a half dozen cloth diapers (great burp cloths, changing pads, emergency breast pads, ect), a "touch-and feel" board book (I love shopping at Marshall's for board books, wooden toys, and puzzles!), and if they live close by, I'll bring over dinner. With friends that are having subsequent babies, I also include a little something for the big brother/sister.
I didn't have any intentions of being AP (I didn't even know of the term until DS was 6 months old) before becoming a parent, so you never know. I would have loved to have received "The Baby Book," then I wouldn't have been doubting everything that we did by following our hearts in the first six months! And since they just release a new edition, you may be able to find the last edition super cheap in the bargain bins at B&N or Borders. Last I saw, they were going for $5.99.