Chicago-Style Citation Quick Guide
Hamilton College, "Writing a Good History Paper"
A nice overview; the discussion of pitfalls in editing/revision is excellent.
Prof. William Cronon on Historical Writing
Prof. William Cronon's excellent guide to historical writing; part of an even larger guide to doing historical research.
How to Organize a Research Paper
Writing Center Handout on History Writing
List of Resources on History Writing
Formulating a Research Question
Making the Most of Research Time
Writing a 4-7 page History Paper (David Herzberg, 1992, Wesleyan University)