Unfortunately I cannot help you on Salamanca (wonderful city that you will certainly like, also because of the pleasant student atmosphere), but some general guidebook tips:
- The Michelin Green Guide also is good for Italy. There's one for Spain too but I haven't used that one and it gets mixed reviews on Amazon.
- For Toledo there's a great guide called "Toledo. The Magic of Three Cultures" (published by Límite Visual and available in Toledo itself). It's part of a series that also includes Lisbon and Santiago de Compostela. Over 400 pages on one city! With photos, stories and maps. Looks a bit like the Eyewitness Travel Guides series (which I like in general for European cities).