I have a job at a boutique litigation firm in NYC this summer, but I don't know that I have much to offer by way of advice. I go to school in NYC, and this firm was participating in my school's OCI program. I didn't have to do any legwork to make connections beforehand.
The firm is less than 40 attorneys, and I was told in my interview that they do not hire attorneys straight out of law school because they are so small. They prefer people with experience, and thus do their hiring laterally. That doesn't affect you for 1L summer, when it's not that important to get a job offer, but it wouldn't be a good situation after 2L, when you're hoping to get an offer that you can keep in your pocket for post-graduation. If you definitely want to do the small firm route, though, and if this place is at all typical, then you might want to plan to work elsewhere for a few years to get some experience/training.