The site Nellie linked contains this brief description of the Investiture:

"Swearing in and investiture of the King at the joint session of the two Houses of the States General in the Nieuwe Kerk. The King will deliver an address and be sworn in. The President of the joint session, Fred de Graaf, will deliver an address and make a solemn declaration, after which members of the States General and the States of Aruba, Curaçao and St Maarten swear an oath or make an affirmation."

This ceremony, which follows the formal abdication of Queen Beatrix, seems more similar to an Inauguration than to a Coronation, though it does happen in a church. The events surrounding the Investiture are also described below the list of guests.