Go to your library and have a browse ... that's what I did.
Now one thing you may notice is this:
The books they've got in the library from the 1970s and into the 1980s will talk about a different style of touring than people do now. Back then, it was all about loading your bicycle to the gills with everything you might imagine you'd need, and touring self-supported. Back then, you brought all the food you figure you'd need for the entire trip, and try to keep to yourself as much as possible. Camping was the way to go, and cycletourists abhored the use of any other form of transportation than cycling. And tours were at least several days long, if not weeks or months.
These days a tour can be anything from a daytour to one of several years. These days you might bring a couple days worth of food with you just in case, but then you shop along the way so that you can interact with the locals and try the local fare etc. You might camp, or stay in a hostel, or stay in a 5-star hotel ... whatever you prefer. And it is still touring if you want to ride a while then take a ferry to another location, then ride a bit more, then catch a train, then ride a bit more, then rent a car, then ride a bit more, etc.
If you scroll partway down my Links page, you'll arrive at the two Touring sections I've got there:
Touring Tips & Ride Reports
and Touring Clubs & Organisations
You'll be able to pick up some tips from the links there.
And then get on your bicycle and go ride!