I found this guide really useful. I arrived in Torshavn from Reykjavik (city airport, not Keflavik) & the guide helped me quickly find the shopping district, the parliament, historic sites & art galleries. There is clear info on transportation links (bus, chopper, ferry, etc.), currency, medical & all hotels/restaurants with price points.
There is also a breakdown of all the islands (not all are inhabited), how to get there & local tour operators.
Because this book helped me plan ahead, I was able to pack a lot into a few days, truly a spectacular place to visit.