How do I set post thumbnails and what dimensions are used?
Deadline uses the WordPress 2.9+ Post Thumbnail feature for all post thumbnails and so you will need to be running version 2.9 or higher of WordPress to use them correctly.
You only need to set the featured image for each post once. Just ensure that your chosen image is 460×280 or larger – the theme will then resize the image multiple times for different scenarios.
Do note that the theme will resize images on upload only, not images that have been uploaded before the theme is activated.
More on using the WordPress Post Thumbnail feature: http://en.support.wordpress.com/featured-images/ More on the WordPress Post Thumbnail Function: http://markjaquith.wordpress.com/2009/12/23/new-in-wordpress-2-9-post-thumbnail-images/