I've started using JIRA OnDemand to manage projects for multiple clients. I would like to invite users from various teams to create and view issues on specific projects. However, out of the box, it seems like JIRA is configured to allow new users to browse issues on all projects. I do not want a new user to be able to see all of my projects, so I would like to restrict new users' access so that they must explicitly be granted permission to browse issues and create new issues on a specific project.
What would be the best way to accomplish this?