In reply to Michael Haywood:
Hi I think the route you are referring to is Directa de Los Martinez, which is on the south face. This is also the abseil descent route for all routes finishing on the summit of Naranjo de Bulnes. So the abseil stations are very well equipped. You will need double ropes to get down. Take careful note of where the last belay/abseil station is before you scramble up to the summit. It can be difficult to spot on the way back down.
The Robin Walker book is the only one in English worth using and will get you up and down. It has very good advice for correctly interpreting the weather in the Picos as well. However it is a bit dated now.
For a wider range of routes and info about areas to escape to if the weather is not so good you will need a Spanish guide book. The best one I know of is Cordillera Cantabrica Escaladas Selectas en Roca (only in Spanish). This is available from Cordee but at a hefty price £40. You can get it much cheaper by buying it out in Spain. To do this you will need to go to Arenas de Cabrales or Potes, two of the main towns. When the weather is bad in the Picos the areas to the south of the range (in the rain shadow) are good to escape to. They are covered in the spanish guide. Some of them are also covered in the recently published Roca Verde - Sport Climbing in North West Spain
Asturias, Cantabria & Leon. This is in English but only covers sport climbing. The spanish guide covers both Trad, sport and what it calls plasir, sort of half way between the two.
This year they had snow in the mountains in June! This made the Spanish national news.
