Rosario's flat is really nice. Two blocks from a bike hire place: that's the way to visit Valencia in our opinion. The place is central, clean, Rosario is really nice and really good host. Totally recommended.
Now, aside from Rosario's flat, just a few things that we will appreciate if someone told us upfront about Valencia: All the people buy bottled water! (It is a bit shocking) We cooked with tap water, but we drank bottled water even for tea. People said that it might be alright for drinking once or twice, but we recommend to have this in mind. Seems that nobody trusts the tap water.
The other thing is that if you need to be very early at the airport, be careful with the times of the metro (subway) and buses. We needed to get the airplane at 6:30 (gates) to depart at 7:00 am. Well, the metro service starts at 5:49 am, so we got just in time to the gate (6:32 am). So if you need to travel very early, better to take a cab or sleep in the airport the night before.