The second book in David Weber's Honor Harrington series. I'd call this formulaic space opera, except that there aren't really that many people doing it any more, and Weber does do a very good job; he finds a few more interesting aspects of the technology he introduced in the first book, he introduces a highly-conservative society, explains how it got that way, and how it's likely to change as a result of the events of the book, and there are Big Space Battles. It's convincing and entertaining, even if it's something of a guilty pleasure.
If you liked the first book in the series, this one's even better; if you didn't then you'll probably hate this one too. Recommended for fans of the genre.