The Staff Lounge or Staff Suite can be an expensive proposition, however if done properly may increase the number of people that you have willing to staff or volunteer at the convention. Most Anime conventions provide a Staff Suite and many other general conventions do too. Sometimes this is part of the Gopher Hole or the Volunteer den.
Larger conventions tend to separate the rooms for walk-up volunteers and staff that have more responsibility. Many Conventions will provide snacks for volunteers and full meals for staff.