Setting up Contribute

Create an article using the Forms Service template and relate your contribute form to it. Secure the article to the user group you'd like to be able to use it. The users in this group should also be members of the CONTRIBUTE group who are eligible to start the contribute workflow.

There's no need to make the other forms available using articles on your site, these are linked to directly from workflow tasks

If you are using Self Service or User Requests, update those articles to include the contribute workflow process.