More and more hostels in Greece established their own websites and to some extend they offer direct booking links from there. But bear in mind that each hostel would only say the very best about themselfs on their sites and some hostels tend to exagerate a little in the way their promote their accommodation. For example "we are the friendliest hostel in Greece", or something like that.

Also the booking systems, these hostel websites have in place, are not always the most reliable, depending on what sort of technology they use. To be on the save side when you plan to book a hostel in Greece is to use one of the three or four really big international hostel booking sites like hostelbookers.com or hostelworld.com. Greece hostels are the cheapest accommodation you can find. Apart from youth hostels there are options for private room rentals, cheap apartment rentals, inns and bed and breakfast accommodation.