Some advice on choosing a neighborhood (New York)

Dear All,

I am considering to move to NY for work, and before I can make a call, I need to do the maths and check how much my cost of living would be over there. I guess rent would play a major role on my expenses, so I would like to ask you guys some questions.

Which neighborhoods do you recommend me to look at? I would like something with a good balance between being safe, not too expensive and not too far from the financial district.

Also, which websites would you recommend me to use for doing some research?

Thanks,
Fabio