I'm traveling to New york city as was looking to rent an apartment, short term. I have, however, heard that rental periods less than a year are illegal in NYC. Is this true? Or are there official websites/companies that nice apartments can be found and legally rented for a week or so? It would be for 5-6 people.
No that is not true, you can rent an apartment in NYC for a week if you needed. NY Habitat is one company I know that specializes in renting NYC apartments or you can go to Sublet.com
Your question immediately made me think of 254 East Vacation and also the Oxbridge Carnegie Hill Apartments on the Upper East Side of Manhattan. These two places are great options for long term stays in an apartment style setting, not like a hotel room. They come equipped with kitchens and appliances. I did some research, you can read more about them both here: http://www.nytix.com/Hotels/locations/neighborhoods/upeast.html