You don't say when you are travelling, but if before Easter there are not too many sites on this route - i use it regularly.
Open all yeat sites are shown in CC Europe 1 guide, but the ones i use are
Mendigorria - just south of Paamplona - ok but facilites very limited early in the year.
Savinan - south of Zaragoza - in the book under Calatayud. Terraced pitches with overhead canopy frames. OK if you have a small van or a mover. Tokens needed for showers, so it gets quite expensive for two for one night. Easy to find from the Zaragoza to Calatayud autovia.
Manzannera - in the book under its own name. OK for overnight, but avoid Friday / Saturday - many local skiers in statics and seasonals. From the new autovia round Teruel towards Valencia look for Sirrion (or Sarrion) and turn off to it. Then continue on old N137 east until Estation de Mora where you will see Manzannera signed. site is at filling station at entrance to village. Pay there in evening - may not be open in morning. Heated toilet block, relatively cheap diesel.
A bit nearer Valencia good site at Navajas. Terraced, some pitches have high curbs. Interesting town and area.
If you don't mind a bit of country road - open but a bit uneven, there is a good shortcut from Magallon to La Alumina which avoids Zaragoza altogether. Magallon is east of Zaragoza on A 68.
Not many rest areas of service stations - suggest you fill up at 1/2 tank. Not all that much HGV traffic either compared with some other routes.
Hope this helps !