I just received the revised edition, The Savage Garden, Revised: Cultivating Carnivorous Plants by Peter D'Amato, as a birthday gift. For a while I held off on buying books about carnivorous plants since I figured I could find any info I needed online and I'd rather spend the money on more plants.
The issue with relying solely on the internet for your information is you really need to do your due diligence in making sure the information you're getting is accurate. Sometimes the responses you get are just rehashed misinformation that the person only read online themselves a few days ago. Or you get a reply from someone who really only has experience in their limited range of growing conditions telling you what is and is not correct.
With a book, especially this revised edition, you're getting information from someone with years and years of CP growing experience.
I consider myself pretty knowledgeable about CP's, at least those genre I grow myself. But even still I find myself learning new things from this book. Plus it's nice to have a quick reference at hand when you need it.
I know there are a lot of great books out there and having not read any of them I'm not saying this one is any better or any worse. But if you're looking for a good book on carnivorous plants I wouldn't hesitate to pick this one up. Since the revised edition just came out a few months ago you can be sure the information is accurate.
I'm sure you can find it for sale a lot of places, but here it is on Amazon.
Also, for those that may not know, Peter D'Amato is the owner of California Carnivores