Up From the Depths is a series of books centered around a fictional zombie outbreak. Unlike other books and films in this genre, the cause for the outbreak is not a returning space probe, rogue comet/meteor/asteroid, a 20,000 year old alien thawed out or some supernatural event.
Staying as far away from the cliche and stereotypical causes, UpftD looks at real world, scientific experimentation for a cause.
Focusing on something that is rarely done with any accuracy, UpftD is a story about several military units before, during and after the outbreak. While the primary focus is on these units there are other characters involved. The range of characters run the gamut from housewives to IT specialists, salvage yard owners to high priced escorts. There's even a group of zombie fanboys who have prepared for just such an event.
If you're looking for something on the same scale as a Tom Clancy novel, the Up From the Depths series might be what you're seeking.