The trilogy is surprise surprise made up of three books.
The Dark Tide
Shadows of Doom
The Darkest Day.
Written by Dennis L. McKiernan
The series is a fantasy story following the basic principals of most fantasy series. "1) Something bad is coming. 2) Oh dear its arrived. 3) Oh crap! We'd better deal with it."
The author says that he loved the Lord of the Rings story and wanted more, and this story is the result. He has created his own fantasy world, and put his version of Hobbits right in the middle. He has made a change to the Hobbit character however. In LotR Hobbits are laid back lazy people, in this trilogy they are presented as a much more "realistic" people. They work hard to make a living and have a strong cadre of Bow armed border guards.
The story is very engaging, I found myself drawn to these less soppy Hobbits and hoping and wating them to succeed. They are not always successful which makes them feel more real and allows your sympathies to come through.
In short, it's an exciting, fun adventure, and has deliberate LotR references and parrellels that make it both familiar and new.