If You plan to visit Sweden in summer, a good choice is to go to Öland, a long and narrow island on the Swedish east coast. There are many small villages to visit on the island with many farms and a slow pace. You could go strawberrypicking, rent a bike to see all the wind mills on the island and dont miss out on the two famous lighthouses that are situated on the southern and northern part of the island respectively.
Öland is very flat and perfect for biking!
Byxelkrok is one very pretty fishing village, in the north. From here You can go with the ferry to another famous island, "Blå Jungfrun", for a daytrip. All over the island there are many cafes and bars with live music so keep an eye open for posters that announce a ive event.
If You go to Öland You have to go to Borgholm! This is where You find the pulse and nightlife, after beach and more. Here You find Solliden, the summer residence for the Swedish Royal Family. Next to it is the famous ruined castle where a lot of concerts are held every summer. Also worth a visit.
The beaches in Köpingsvik, just 5 km north from Borgholm are really great. This is definitely where the locals go.
If You like sailing this is a very good place! rent Your own boat or join a sailing school.