I love incorporating cliff-hangers into my books (the word alone conjures up an image of people hanging by the tips of their fingers as they wait to be rescued.) A good cliff-hanger makes the reader want to turn the page to see what happens next. The celluloid equivalent was the old Flash Gordon series, where you had to tune in the following week to see if Flash and Dale survived.
The cliff-hanger is another way of maintaining suspense, but it can become jaded if overused.
Fangtooth is going well at the moment. I've started reading my research books, and have already picked up a few tips that can be incorporated into the story. The hard part is making the factual pieces flow, and not seem as though they were copied straight from a book. But then that's what writing is all about.