I want to get into politics...but where do I start?

Please help me...I am increasingly interested in politics. I am a recent college graduate looking for a way to find out what kind of government work would be best for me. I am applying to intern with an emblyman, and I have thought of working on some campaigns...but I am kind of confused. What kind of internships are best or look the best on resumes for graduate school (in public policy?). I consider myself a democrat but I have applied for positions with Republicans. Does this really matter in the long run? I did an intership with the city planning department of my city but now I think I want to do some kind of legislative work. Any advice would be apprecciated thatnks!!