Sometimes the simple questions are the hardest. It took a couple of days to contact anyone with half an idea of what was happening at the top of Rockefeller Center and I managed to get half an answer. Hours are yet to be determined, all we know is that it will be very expensive. Once again I have to apologize for being late getting back to you. As I said in my e-mail, Susie and Jim were doing some heavy maintenance on the Jim's Deli hotel section and weren't able to publish any new material until their updates were completed.
Some hostels do take reservations over the internet, whether by e-mail or an online form.
You can make reservations online for the Aladdin Hostel and the Mid-City Guesthouse through the Jim's Deli hostel pages . Also, Susie and Jim have gone back and, during the maintenance update, included links to New York Hostel, Banana Bungalow, Blue Rabbit Hostel, Sugar Hill Hostel, Chelsea International Hostel, Hostelling International, Jazz on the Park and the Big Apple Hostel. They might take reservations, they might not, they're going to play it by ear. During high-traffic periods, such as the summer season, most hostels operate on a first come, first served basis. Thanks to your question I'll be keeping on eye on this and will post any changes in the Jim's Deli newsletter.