It is recommended to schedule your air travel to arrive at Brussels airport. For more information please check the website of Brussels Airport. From other airports you can also get easily to Brussels and Ghent. Amsterdam (Schiphol), Paris, Frankfurt and London are all connected with fast train systems (see Europe Travel website).
From Brussels airport (Zaventem) you can easily reach Ghent by train. Some direct fast trains bring you to the main railway station Gent-Sint-Pieters in about 52 minutes. There is also a slower track (via the city of Aalst – approx. 1h22) and hence it can sometimes be useful to change trains in Brussels (approx. 1h travel time). As time schedules could differ weekdays and weekends you can find 2 sets of personal time table files giving an overview for the incoming train options 02 up to 04 June as well as outbound travel to the airport for 08 up to 10 June. Of course you can also check the website of the Belgian Rail.