Don't miss these other scheduling options: setting a promise date and setting a delay date

On Hold

You can put any item on hold, perhaps because the budget isn’t approved, resources haven’t been hired, or you are not ready to schedule the work. 

You put an item on hold via the scheduling tab in the edit pane.  Putting a project or tasklist on hold will put all items within that container on hold.  The items will display the "on hold" icon in the left margin, and they will no longer have schedule bars: