Italy -

Every year in October / November four professional Italian restaurant guides - some say even gastronomical bibles - are published.

Guide de Michelin, Italia Alberghi & ristoranti, 
Ristoranti d'Italia del Gambero Rosso,
L'Espresso, I ristoranti d'Italia, 
Slow Food, Osterie d'Italia 2015. Sussidiario del mangiarbere all'italian, 

Very useful could be also the journal Ristoranti http://www.ristorantiweb.com/

Special PDF Version of FoodService Europe & Middle East 2011/4.
Pan-European Survey: Vegetarian Restaurants Part I. Shifting out of the Eco-freak Corner into Mainstream Society. Page 8-18. Contributing Author: Italy: Flavia Fresia

Some basic nformation offers the printed guide  "Viaggia vegan. Guida Italiana. Turismo & Ristorazione. Prefazione di Salvini Simone. The guides costs around € 20,-  at amazon.it.

The Michelin Red Guides and the Gault Millau Guides have become widely known as the world’s most respected sources of restaurant and hotel evaluations.  But from a vegetarian or especially vegan point of view the problem is that both guides, the Michelin Guides and the Gault Millau are nearly "totally meat obsessed".   Michelin Guide Italy - 2300 selected restaurants with only 1!? vegetarian restaurant.

More European and national  Restaurant Guides

In German language you find the PDF of a very usefull portrait about veg restaurants in Sicily.