Political Economy/ Public Policy?

[Choatie]

Hi,
I was wondering about graduate programs in Political Economy or Public Policy....
What are the programs like? What sort of jobs are available upon graduation (with a Masters or PhD) ?
What should one, as an undergraduate approaching junior year, do in order to best prepare herself for admission into these programs?
Do internships matter and if so, which ones?
What part of the application (GRE, GPA, letters of rec, essays, etc.) matter most in the admissions process?

Any other advice/information for someone who does not know very much about PhDs/Masters in this field?

I appreciate any and all feedback provided.