Tutorial Chair
The Tutorial Chair is responsible for requesting tutorial proposals and making final selections. When appropriate, the tutorial chair can recruit a small committee to help evaluate the proposals and make final decisions. In years when more than one person co-chair, this might not be necessary.
In recent years, the selection of tutorials has been made in unison with other conferences such as NAACL, EACL, AACL, EMNLP, etc. as appropriate. This helps ensure a variety of topics across conference locations and creates a more diverse pool for submissions. However, the conference-specific tutorial chair will need to coordinate with the local chair to understand room availability (e.g., how many tutorials are there room for).
Thus, the tutorial chairs then become a defacto committee for tutorials across all conferences. Hopefully the chairs have been selected so that there are a variety of skills represented on the committee so that all tutorials can be fairly evaluated. If not, it may be useful to solicit external reviews (however, make sure to allow sufficient time for this in your calendar). Information about recent tutorials and attendance can be used to decide which tutorials are likely to be of interest. Balance between different topic areas and diversity in presenters is desirable, but not strictly necessary. One downside of the committee structure for tutorials is that the first conference in the calendar has a more rushed timeframe. That organizer (usually EACL or NAACL) will then need to impose appropriate submission and review deadlines on all tutorials (in conjunction with their general chair).
After tutorials have been selected, more responsibility devolves to the conference specific tutorial chairs, who are responsible for collecting one page tutorial abstracts and materials for the proceedings. Tutorial submissions often vary greatly in depth, concreteness, and thoroughness, so the tutorial chair should make expectations (both what is required and when it is required) clear upon acceptance to give the tutorial authors enough time to respond to requests.
The dates that affect internal deadlines are: publicizing tutorials in time so that people can register (deadline set by general chair and publicity chair) and getting tutorial information into proceedings (publications chair). Special presentation and computer requirements should be communicated to the local organizers.