As the owner of a Google doc, you can publish it to the Web at any time. If you want to allow your collaborators to publish documents to your site, make sure the option labeled 'Editors will be allowed to add people and change the permissions' at the bottom of the 'Sharing settings' window is selected (or click Change to change it). Collaborators can then publish, invite others to edit or view the document, forward invitations to mailing lists, and see who else has viewing or editing permissions.

If the option 'Editors will be allowed to add people and change the permissions' isn't selected, collaborators won't see Publish as web page... in their sharing menu.

Note: Those with only viewing access cannot publish.