
I haven't read a ton of Charles Stross' books, but I've read enough to know that I quite like his writing. I'm having trouble describing it - it's a bit absurdist but without being outright silly, I suppose? More like Terry Pratchett than like Piers Anthony, I guess I'm trying to say.
This particular book was first published as a serial across a year of magazine issues, I gather from the copyright. It follows an IT guy turned "agent" with a British secret government agency who deal with the occult. The magic, such as it is, is styled as Lovecraftian - gates to other worlds, possessions, etc., and brought to current times as being controllable via tech + math + rituals. Sounds goofy? Yeah, it is, but it's fun. I enjoyed the ridiculous bureaucracy mixed with occult horror as a genre, and the characters fit nicely into it. The book is a smooth arc of the character becoming a field agent and a solid stand alone.
The compiled version of The Atrocity Archives also comes with the (2005 Hugo award-winning) novella The Concrete Jungle. I didn't truthfully enjoy the novella as much. It was more fast paced and felt a lot like just playing in the world rather than a thought out plot. I suppose that can be inherent to the shorter length, but it didn't catch me as much.
Stross has a history of writing near future scifi that tends to get negated or proved as time goes on (see his set of short stories, "Toast", if that's interesting to you: published by Stross as Creative Commons here:
http://www.antipope.org/charlie/blog-static/fiction/toast/toast-intro.html), and the notable moment in these books was his passing reference to the international security agencies sharing information so that none of them were technically the ones collecting it on their own citizens. Sigh.