Simple guide

You can get a specific credential for the El Salvador at the Santa Maria Albergue in leon, it cost 2 e and gives info on the route, ie albergues, distances, elevation profile, facilities along the way!
The way is very well marked, no other guide is necessary! I walked this route beginning of June, took 5 days, but possible to make it 6/7 days also. Its a very nice camino and you can get a certificate in Oviedo when you get there!
Buen Camino
Aidan

Gronze.com has an online guide if you have a smart phone or Ipad? It also lists accommodations along the way. Several of the small towns along this route do not have restaurants, bars or tienda's. I recommend you carry some food with you.

Ultreya,
Joe