We are visiting Trollhattan in early June 2015 for Saab convention any advice on what city to fly into from USA hotels or b and b
Have you checked with the convention organizers for hotel and transportation advice? Major conferences usually have this kind of information available for their attendees.
Looking on Wikipedia, I see that Trollhattan is 75 km north of Gothenburg, Sweden's second largest city, which has a major airport. Trollhatttan has its own airport, but Wikipedia shows that its only flights are to Stockholm's domestic airport, Bromma; therefore, it's going to be a hassle to fly there from the US.