In reply to ralphio:
I've got the Plaisir Alpin, I find it most useful for the less well-known easy climbs in the eastern part of Switzerland.
The list of mountains it covers, with almost always just the normal routes described, is on the publisher's web page:
http://www.filidor.ch/Pages/Book.aspx?Id=17.
For each route it gives a very short route description in French, German and English (in place of Italian) in the 2008 print, plus a rough map and a picture or photo of the route.
I would hesitate to recommend it just for one trip to the Valais, but looking at the list of mountains on the website will give you a useful list of the easier possibilities. But speaking from experience, surely there is something better for acclimatisation than the Stellihorn!
Note that Swiss maps are on-line here:
http://map.geo.admin.ch/
There's another site better to print maps from, but I don't find it right now.