I don't have any personal experience, but my fiancee's sister-in-law's uncle (!) lived in Iceland for some time and he said it is entirely different from any other language and you can't rely on cognates to make things easy. OTOH, if you have a "knack" for languages, you'll still get it. He was raised bilingual (English and Spanish) and said that he was able to pick it up fairly easy while he was living there.