It's become somewhat of a cliche, but Tuscany is a great place to tour. Start in Florence, work your way south through Siena and the area just south of Siena (Montepulciano, Montalcino, etc.). Umbria is nice too. Spoleto, Assissi, the Monte Sibilline area are all great places to ride. Two things to be aware of: The terrain can be very steep, and by July tourist season will be in full swing. Of course, by July tourist season will be in full swing all over Europe, so you'll just have to deal with that. North of Lucca, the part of Tuscany known as the Garfagnana is supposed to be very unspoiled and scenic, although I haven't been there yet.
The Pyrenees are a great place to ride, very scenic, but the roads can be steep and it can get very hot there in the summer. Also, taking a bicycle on a French TGV train (high speed, long distance train) is a little more involved than a Dutch or German train.
Closer to home, there's the Alsace-Lorraine area and the Vosges mountains south of Strasbourg and west of the Rhine river. This area was part of Germany before WWI, and became part of France at the end of WWI. Lots of half-German, half-French place names, and a lot of people still speak German.
Lonely Planet publishes excellent cycling guides to Italy and France, it would be worth looking through them for some ideas.
The Touring Club Italiano 1:200,000 regional maps are great for cycle touring, get them from www.trektools.com
in this country, or from the TCI website, www.touringclub.it
. Michelin and IGN (Institut Geographique Nationale) have excellent road maps of France.