Everything to do with using your own website to advertise your rental property. Design, usability, hosting, getting listed on the search engines, optimising your site, pay-per-click, etc, etc.
I am just in the process of creating a new-look website with Wordpress.
I don't want a booking system plug-in, just a calendar plug-in.
Does anyone use the Premium version of WP Simple Booking Calendar? If so, have you used it to export your calendar to other sites using the iCal facility? Have you found it reliable and easy to use?