Images for events are 770px width, and 450px height.
The bottom 100px (in height) are possibly covered by a caption. (eg. The carousel on the homepage)
There's a .psd-template available.
Posts should contain answers to the W-questions: What, Who, Where, When
Alternatively, you can add data like the Capacity, Competetions, Prices, Ticket Price, etc.
Sponsors can not be added to a post, 1 or two head sponsors can be mentioned though.
Also, a maximum of 2 sponsor(logo)s can be shown in the header image. Both covering maximum 1/8th of the image's whitespace.