Living in NYC is an amazing experience. If you are relocating, I recommend staying in the city first, before moving into Brooklyn, Astoria or NJ for example. Williamsburg is hot right now, but don't expect to pay less to live in the good parts. I have seen others cut corners and live outside of the popular pockets and it's the equivalent of me moving to the Sunset - close but no cigar.
Commute: Within Manhattan your travel will be 5-25 minutes depending on how far you're going. Cabs are cheap when your in a hurry. If you enjoy walking, even better. Bicycles are taking over NYC, it's been an amazing transformation as of recent and if you enjoy riding, thats a bonus.
Work: I do freelance development and there is alot of business in the city, ALOT. I get calls every week for developer roles. Another great part of being in the city is the diversity across all boards. You will meet people from all over the world, working in so many different industries...it will give you an amazing perspective.
Rent: Expect to pay at least $1800 for a small studio or a room share in a nice 2 bedroom apartment. You can definitely find cheaper places in the city, but where you live in the city defines you and your lifestyle to an extent.
Areas to consider: (without knowing much about you)
East Village, West Village, Lower East Side, Chelsea, Hell's Kitchen, Union Square, Murray Hill, Upper West Side, Upper East Side, Midtown (East and West). Great food, convenient, always busy.
Meeting people:
There are many meetups and networking events, but your work will be your gateway to expanding your circle. If your single, NYC is a huge dating market. Get some good pics, throw it up on Tinder, Match, Howaboutwe and have fun. Also there are great places like 3rd Ward in Williamsburg which is just a few stops away on the L Train and they have an amazing creative community. Going back to my emphasis of staying in the city, it's 100X easier to meet people while living there than commuting into it.