Hi, Robin!
Great question!
There are so many tricks of the trade when writing page turners.
Briefly: thoughts slow things down. Never have a character thinking by himself/ herself when you're writing a page turner. Thoughts are for giving the reader a breather when the action has been going non-stop.
The best thing is action. The old adage "show me, don't tell me." Action propels the reader forward.
I also don't like flashbacks. Stephen King said once that every time he read a flashback he thought of the old movies where the character got a funny look on his/her face and things went fuzzy... Flashbacks bring a reader back in time. You want to keep propelling them forward.
Never write more than three paragraphs of narrative (at a time) if you want a page-turner.
Dialogue propels a story forward; the reader can flip through dialogue very quickly, but it isn't as good as something physically happening.
Stay away from talking heads.
Change locales.
And leave each chapter with something hanging, so the reader has to go to the next chapter. They can't manage to put the book down!
A really good book to see how each chapter leaves you hanging is "What Dreams May Come". Regardless of what you think of the storyline, the author ends each chapter in such a way that you can't stop reading. (The book is very different from the movie, as they all are...)
What propels a story forward is conflict, conflict, conflict. Nobody wants to read about someone where everything is going right. Every single thing they try to do has to be like climbing a mountain. Especially with suspense. The noose has to keep tightening until you, the reader, feel so much suspense you can barely breathe.
A great movie to watch for how they work with suspense is "Out of Time" with Denzel Washington. I buy movies (only DVD) and study them. The reason I buy only DVD's (as opposed to tapes) is the DVDs come with the Director's comments and background info, which I've found incredible for a writer, especially if you would someday like for your book to be made into a movie.
Hope this helps!