The Eastercon produces a number of "publications"; things that are sent out to all or some of the members but are indentical in content (like a newsletter) rather than individual letters.
An Eastercon typically produces five Progress Reports, see the Timeline for more details of when each comes out.
Progress Report ZeroEdit
This is distributed as soon as the convention wins the bid. It contains details of the membership rates, the name of the hotel/site, the names of the Guests, contact information for the convention and any other information that the Committee want to publicise at this point.
Progress Report OneEdit
Basically this comes out over a year before the convention, and usually contains some biographical information on the Guests, perhaps some more thoughts about the convention's Theme or philosophy and perhaps some information about competitions and such. It's main purpose is to let you know that the committee is still there and the convention is still going ahead.
Progress Report TwoEdit
Comes out a year before the convention and starts to have information about specific programme items and streams. It also usually includes the hotel booking forms and volunteer forms.
Progress Report ThreeEdit
Comes out a few months before the convention and is now looking for people to help with specific areas and includes articles on any major events at the con you may want to prepare for (writers workshops, robotics, Masquerade etc.)
Progress Report FourEdit
A small publication, maybe six weeks before the convention, that tells you how to find the hotel, anything you need to bring with you and sometimes includes information on the label of the envelope (such as which nights you're booked for, and your membership number) which will be useful to have with you when you arrive at the convention.
In recent years it has become more common for conventions to print their Souvenir Book after the convention, and fill it with photographs and conreports of the convention.