When planning your trip to Iceland we recommend that you visit the official tourism information sites:
Here at the Inspired by Iceland, you can find a list of places to stay, from camping places to fancy hotels. If you want to stay close to the start of the race 101 Reykjavik is the neighbourhood you should choose but 107 and 105 is also close by. The race starts on street Lækjargata, close to Lækjargata 6, 101 Reykjavik. The race EXPO is at Engjavegur 8, 104 Reykjavik, about 43 minutes walk from the start of the race.