American graduate student looking for studio in Paris

I'm an American graduate student and will be studying economics at the University of Paris 13 this fall. I'm arriving in Paris next week and will be staying through mid February. I am on an Erasmus Mundus scholarship and will be receiving a regular stipend from which I can pay rent. I do not speak French.

I'm looking for any studio with relatively easy access to Gare du Nord and would like to stay around 600 euro per month if possible. I'm flying into Paris in a few days and would really like to get a place locked down before I leave. 

Would be willing to consider a room in a shared flat. 

I am currently in the United States, so I would not recommend calling from Europe. 

J.Christopher Proctor