This one is easy for me to give some quick hints on: It's no problem to find shops selling gluten-free foods in places that have more than a few hundred inhabitants. The best way to find specific addresses is using the very handy search function of the supermarket chain with the most extensive gluten-free offer, ICA.
Here's a how-to for non-Swedish speakers: Put the name of your place into the "Ort" field (you have to use the Swedish special characters), check "vänliga varor" and press "Sök". You'll get the addresses and phone numbers of the shops that sell gluten-free products. Click the shop's name to find the opening hours ("Öppettider") and more information, click "Se på karta" to see it on a map.
Anyway, just about any other decently sized supermarket will have gluten-free foods, too :-)