I was lucky to go to Valencia in Spain for the Fallas, one of spain's major festival. just incredible, it is unique. I had a hard time finding an accommodation at this time of the year but finally http://www.accommodation-valencia.com did the job, and a pretty good one! So use them, they are friendly and speak english, french and spanish. The apartment I booked was close to the Carmen, very clean and well equiped. The staff is professionnal and friendly.

I stayed a month ago in Like at Home, a cool nice hostal in the centre of Valencia. Close to PLaza del Mercado and the Mercado itself, in the back of La Lonja building. There are single, double and some shared rooms. The price was extremely cheap for a place where u can use the kitchen and make some friends from all over the world. Clean and cool. For a double room I paid €26, but u can pay almost €14 if u'd share the room. It's not so quiet and always good music there lots of good wibes. They don't close at night , so u can go out and there's no problem. Don't miss El Carme, the neighbourhood where most of the pubs and bars are located. It's not far from the train station (Estacion Nord), but it's not really easy to find, but don't give up. If u r gonna book by email make u sure to pay at least the first night, no matter what was the reply and print every email you receive.