Type "Running Head," followed by a colon and a space, in the header of your title page.
Type the title of your paper in capitals immediately after. The full running head should look something like this:
Running Head: STUDY ON THE EFFECTS OF TOBACCO
Align the header to the left of the title page.
Insert only the title, in capitals and without "Running Head," in the header of all subsequent pages of your manuscript. Align left every time.