As Domi mentiones, the easiest way is to use Sonatype's free hosting because to get your artifacts to Maven Central you must first upload them to an "approved forge" - such as Sonatype.
I've written a short guide that describes how to get started with Sonatype whether you use Maven or not to build your OSS project. They have their own guide but it isn't as clear as it should, so I've added those missing bits to my post and I link to the original guide where appropriate. Check http://theholyjava.wordpress.com/2010/02/07/releasing-a-project-to-maven-centr/
