This is a good book to introduce you to Bicycle Touring. It has a really good chapter on training, with advice on building up enough weekly miles to comfortably bike a century (100 miles in a day) or start off on tour.
Also another chapter discussed the different types of touring. The simplest type is supported tours: where all you have to carry is a few bottles of water, your bike tools and a rain coat, and the rest of your luggage (usually a extra large duffel bag) is carted ahead on a van. The next step up is "credit card" touring where you bike from one motel or B&B to the next, carrying all of your clothes with you, but do not need to carry a tent or food or cooking equipment. Then the big one: fully supported touring where you carry everything on your bike: tent, sleeping bag, water, extra clothes, food, camp stove and pots. The author points out its not as rigorous as backpacking however, because you really only need to carry a days supply of food at a time and since your on the road its easy to resupply water and food a few times a day.
Another chapter covers the dangers and pitfalls of touring: weather, auto traffic, flat tires, broken spokes. And the final chapter covers travelling to your tour starting point via plane, train, or bus. And there is even a handy appendix with supported week long tours in different states. I found three intense week-long tours here in colorado.
A good resource for bicyclists who want to try out touring.