The application deadline for the Herrschner's Afghan Contest 2013 is coming up fast - June 15th. For more information, go to their website. Speaking from experience, they are some really terrific people to deal with!
In a nutshell, all you have to do is download and fill out the application and get it back to them by the June 15th deadline. They send you the submission tag. Then get busy on finishing that afghan! The finished 'ghan is due July 15th.
Obviously, not everyone can win. One nice thing about this contest is that Herrschner's may opt to purchase the non-winning, honorable mention designs. They will contact those they are interested in late summer. It is a fun way to start getting published as a designer.