I've been wanting to read the book for some time now, just haven't gotten around to it. I love the movie (& yes I too hear it was difficult to make... everybody kind of weirded out). So you would recommend the book?
Would I recommend the book? Personally, I'd recommend everything Joseph Conrad wrote- but that's just me. Some people think he is too verbose. I love the way he writes. Conrad lovers have their own personal favorite from his books and it would be easy to spend a lot of time debating the merit of each one. If you were really going to "do" Joe Conrad- I would say read all his other books and save Heart of Darkness for very last as the dessert- for it
is his crowning achievement even if it isn't every Conrad lover's favorite (I like Lord Jim and Nostromo best of all). That's just me though; it's kind of depressing to get through all of a great (but dead) author's work and realize that that's the end of the line for that particular bit of enjoyment.
Ach, I'm rambling... Go on and read Heart of Darkness and if you like it, keep in mind that he's got some more good books as well. Yes- I would recommend it. It's also interesting to read lectures and short essays on the book after you're finished to see all the interpretations different Professors have on it and of course the book will shed even more light on Apocolypse Now. It should make your future viewings of that movie a new/different experience. Heart of Darkness was my intro to Conrad and I'm sure it was for many others as well.