I am a Masters student in history with an emphasis in American but specifically women's history. My problem is historical theory. I've taken a theory course and read all the books written by the greats. Foucault, Braudel, Wallerstein and the like. But honestly I have a hard time understanding them. Is there any book or resource or even a "historical theory for dummies" book out there that could help me understand what I am missing? Anything would be helpful.
Might not be exactly what you are looking for, but Michael Bentley's Modern Historiography an Introduction is worth a look through. It is pretty short (about 160 pages) and looks at about 14 different schools of thought.
Two books:
Herbert Butterfield, The Whig Interpretation of History
David Hackett Fischer, Historians' Fallacies
Are good starts.
I don't put much (any) weight on pure theorists like Foucault, nor does my (good) program.
It helped me a lot to actually read books based on these theoretical deliberations. There is nothing like seeing theory applied. Also, for most of these theories, there are introductory books such as Foucault: A Very Short Introduction. Keep in mind that not every theory is useful for your own interests, for example you should not focus too much energy on understanding Wallerstein in-depth if your field is American womens' history.
By the way, /r/AskHistorians has a weekly feature post dedicated to historical theory, Theory Thursday.