The Reykjavík Grapevine
The Reykjavík Grapevine is a free alternative magazine in English published 18 times a year with an online version: grapevine.is
Iceland Review is a respected magazine in english with an online version here.
There are several brochures you can pick up in tourinst information stands including Around Iceland that promises to be "a complete travel handbook that lists all places to stay, museums, tours, things to do, etc. There is also a german version, check out their website heimur.is