Chess Fundamentals, ex 55, queen sac???

After Nxh3 (I'm assuming that you meant blacks rook 6th gxh3 kf3 I don't see what black has, revealeds fail due to either Ke2 or Kxe4

In my copy of Chess Fundamentals, the reader is encouraged to find all winning variations after 39. ... Qh3+. I don't see a queen sacrifice variation though.

in the position that was given Qh3+ sacs the queen, but to me it looks as if you are just hanging the queen for nothing.

There is more than one way to win. I still don't see a queen sacrifice though. However, the game ends with a queen sacrifice on move 44!
SLOBess, I think your diagram is not correct, at least the knight should be on e2. Does that help?
A copy of Chess Fundamentals with algebraic notation might help also: http://elranchodepachoii.files.wordpress.com/EDEED23F-5561-4192-9326-959AC800AE25/FinalDownload/DownloadId-511085C9FFDD1F9A3940F278A69ECE4D/EDEED23F-5561-4192-9326-959AC800AE25/2013/01/chess-fundamentals-capablanca.pdf