The nearest airport is the regional airport Paderborn/Lippstadt in Ahden (about 45 km away). From there you go by car as follows: Bundesstrasse (Federal road) 1 towards Paderborn, there on to autobahn A33 towards Bielefeld, at the crossing Bielefeld (Kreuz Bielefeld), on to A2 towards Dortmund until the exit 24 Gütersloh/Verl. From there, please follow instructions at "by car".
The largest airport in the region is Hannover (about 120 km away). From there you reach Gütersloh by train or by car via autobahn A2 (see above). You can reach Gütersloh also via the regional airports Dortmund (about 60 km away) or Münster-Osnabrück (about 45 km away). From Dortmund, you also take the autobahn A2 towards Oberhausen-Hannover. From Münster, you reach Gütersloh via the Bundesstrasse (Federal road) 64 (via Warendorf).