Air
You can easily get to Jönköping via Växjö Smaland Airport from: 

Smaland Airport <-> Düsseldorf Weeze
With Ryanair Mondays and Fridays.

Smaland Airport <-> Stockholm Arlanda
With Skyways daily, except Saturdays.

Get to Jönköping from Växjö Smaland Airport by:

 Coach (1 h 30 min)
There is a direct Swebus Express service from Smaland Airport to Jönköping. 
 
 Rail (1 h 45 min)
First an airport coach or airport taxi to Växjö central station, then by rail with SJ or Merresor.

 Taxi (1 h 30 min)
Taxis can be found outside the terminal building. You can book a Flygtaxi in connection with your flight.

 Hire car (1 h 30 min)
The following car hire companies are represented at Smaland Airport:
Smålandsbilen, Avis, Europcar, Hertz