Eyewitness travel guides have lots of pictures and diagrams. They're good for planning but a little heavy for carrying around. This one covers all areas of Milan and the northern Italy Lakes region.
Lonely Planet has local tips, maps, itineraries, and lots of recommendations for places to go around the lakes and in nearby cities and towns.
Eyewitness travel guides are known for their great photos. The top 10 guide covers the top recommended things to do in the lakes region and nearby Milan.
Insight's guide has color photos, a touring map, suggested drives, and recommendations for where to go. It also covers nearby cities.
The Rough Guide has highlights of the lakes, what to see, outdoor activities, practical tips, and reviews of hotels and restaurants.
Lombardy and the Italian Lakes, from Cadogan guides, is a comprehensive guidebook covering the Lakes District, Milan, and the region of Lombardy. It's a good travel guide if you're going to spend more than a few days in the region.