You find the tourist office in Linköping on Östgötagatan 5. You can get all information you need from them about Linköping and also the region Östergötland. The stuff here will inform you what you can do in Linköping and Östergötland. Dont be shy, ask if they can give you maps and other free brochures that you might need during your trip and visit in this area.
When I travel abroad and go to a foreign country that doesn't speak English as a first language I usually try to learn some words to help me get by (although since I am staying here so long I have just started language classes). So I'll list some Swedish words here that might help. Don't worry if you can't remember them, just remember the first one, as almost everyone in Linköping speaks some English (most that I have met so far speak it quite fluently).
Do you speak English?: Talar du engelska?
My name is...: Jag heter...
Please/Thank you: Tack (pronounced like 'Tuhk')
How are you?: Hur är det?
Good thanks, and you?: Bra tack, och du?
I don't understand: Jag förstår inte (förstår = furr-stoar)
For further words or help with Swedish, there is a link below to a good online Swedish-English/English-Swedish dictionary.
In Linköping lies Saab Aerospace, the Swedish company that has produced fighters like The Flying Barrel, Draken, Viggen and the new 4th generation fighter Gripen.
From Linköpings airfield (the same airfield as the airport uses) Saab does test flights at an almost daily basis. Therefor don't be surprised if you hear the roar of an afterburner engine and a sleek fighter screams past above you.