Michael,
You would have to create a Report on the Work Item type so that you can see financial fields no matter the work item type (Project, Milestone or Task). This will also allow you to select any fields you which will show in the grid similar to the data you see in the Work Plan of a Project.
To show forecasted cost per month, you will need to create a graph that shows by date, showing by date will provide the option to show by week, month, quarter.
For further information, here is the latest recording of the Reports and Dashboards Training...