Advice about moving to Boston please.?

[wheelieanne]

I am relocating to Boston by the end of February. I haven't visited the city before, but have always wanted to live there. I am going to be working at a large law firm in the Financial district. I am interested in information about the various neighborhoods and surrounding towns; I have heard that Haverhill is nice, but the commute would be long. I have found a ton of places to live on Craigslist, but I just don't know which neighborhood would be the best for me.
Here is a bit about me:
28 years old
Female
Single
Looking to make friends too (I only have a couple close to Boston)
Social drinker
College graduate

So basically, I am looking to make a fresh start in a new city with all that accompanies that. What are the pros and cons of the different neighborhoods? What does each have to offer as far as a social scene, that isn't too undergrad-related?

I appreciate any advice! Thanks!