room booking

Our library is looking for a way for customers to request a room or equipment reservation from our Drupal site. We would like our staff to be able to select a room for library-sponsored events and programs as well while they are entering the details about the upcoming program. Has anyone got a recipe of modules that might help accomplish this task without being too difficult for the public? If possible, we would like to incorporate a financial piece for accepting deposits.

I want to create a Drupal module for visitors to book rooms or entire buildings. It's intended for buildings that have publicly-accessible meeting rooms, study rooms, or banquet halls. The module would be built to allow managers to use it in tandem with Google Calendar for greater flexibility: sometimes bookings are made or changed in-person, and Google Calendar is better suited for quick and visual edits. This would just be a single possible implementation; I intend to also create a generic booking API along with this.