Book IV is all Frodo and Sam and it's everything that happens to them from the time they leave the company up to just after the Shelob-struck Frodo is taken by the enemy. So if you've seen the movies and know what happens there and you've decided to read the books for fun? For the love of all that is holy, take my advice and skip Book IV. Well except the bit where they run into Faramir. Book!fandom was totally justified in being pissed off at what was done to Faramir, btw (he shows up for like 10 pages in Book IV...it's the highpoint of the entire section). In the book, he's never tempted by the ring and he's certainly not some whiny ass crybaby in need of a hug from Pops. He's grave and wise and kind and confident...He never comes across as a threat to Frodo or Sam and there's no Abu Gharib-style beatdown of Gollum in order to extract information. So in short, they pretty much wrote a new character and gave him the same name as a guy in the book. I can't imagine what it must have felt like to have imagined Faramir in your head one way for all those years and then have been given Fran and Phillipa's watered down version. Invasion of The Body Snatchers much? Oh, and Sam and Frodo never have that fight and Frodo never sends Sam off TO HIS CERTAIN DOOM. Good to know.
Best bit -> when Frodo is recounting Gandalf's fall at Moria and Faramir says that it must have irked his brother to have been forced to retreat from the bridge. Frodo: "He was the last, but Aragorn was forced to lead us. He alone knew the way after Gandalf's fall. But had there not been us lesser folk to care for, I do not think that either he or Boromir would have fled."
Anyway, point of post...I was very glad when I turned to Book V (being the first part of ROTK) and I spotted the names Gandalf and Pippin in the first sentence.