About the location
New York is one of those cities which offers something for every type of photographer, no matter if you like architecture, urban, people or any other type of photography. There are probably dozens of daily shootings for magazines you can't miss when you travel around the city. Especially Brooklyn seems to be a preferred place for those photos.
The most popular locations for photographers in New York are the Brooklyn Bridge with the skyline in the background during sunset and the views from observation decks like Top of The Rock, which are extremely crowded during sunset, so you definitely need to be there very early and book your time slot a few days in advance. Otherwise you may be unlucky and not get up there at all.
Places like the Statue of Liberty, Central Park or Times Square are just extremely touristic, so it's probably better to visit them without your full camera equipment and just enjoy the vibe of this mega city.
The time to visit the Big Apple doesn't matter that much, because every season has it's own benefits. Very popular is the time before Christmas, but as a photographer you should definitely prefer the late summer around 09/11 when you have the chance to get a very special photo at that day when those two huge light beams are visible everywhere in the city, symbolizing the missing twin towers. The event is called "Tribute in Light" and definitely worth it to be around New York when it's happening.