It's easy since you can reach Norsborg by either Metro or bus. By Metro its about 45 minutes from T-centralen (Red Line) and it's the final end station on the "red" south line. If you come here to look at the historical remains which are all located close to the seaside & forest area where no bus or Metro stop I highly recommend you not to travel here alone. Bring someone who has been to Norsborg before and can helpt locate the sites for you. From the Metro theres a 30 minutes walk.
What to buy: Here you can buy everything, good and bad things. Usually people call the church and then they come and pick up what they dont want to keep in their homes and then this shop sells it to people who want to have it. Perfect business idea. Recycling. Good for everyone.
As I mentioned in the transportation tip for Norsborg, I suggest you have a companion with you who knows the local area. That is, if you've never been there before... Norsborg is a surburbian area and is wellknown for its high criminality rate. Do not stop any person for asking a question and if you're provoked... never, ever get into an argument with teenage boys "gang-boys" who hovers in streets & Metro. At most light hours Norsborg is a safe place, but as a regular tip do keep your eyes open.