Often a recommended list of suitable properties is supplied with the invitation.
It is a good idea for the hosts to block-book local hotels and guesthouses to secure rooms (this may also secure a discounted rate). Guests can then 'phone up and change the booking into their name.
If a block booking is made, an early check-in should be organised to ensure that guests can check-into their rooms and get ready before they have to leave for the ceremony.
If an early check-in is not possible, a secure area for guests to leave their luggage should be arranged.
If the reception is taking place in a hotel, it is often possible to book all of the hotel's guest rooms at a favourable rate.