Flughafen Münster/Osnabrück International Airport
The distance between the Flughafen Münster/Osnabrück International Airport (FMO) and Münster is about 30 km. The FMO has its own bus station. It takes 35 minutes and about € 6 to travel by express bus to Münster. The same price but more time (about 50 minutes) applies with respect to the scheduled public-transit bus.
Travelling from FMO to the city centre by taxi is another, more expensive option, which may save you some time but might cost you about € 35.
Most hotel web-sites will give you travel directions by public transport. Otherwise, you may consult the web-site of the local public transport company, the RVM, which also provides various maps.
Further details are available from the airport homepage.