It's almost a cliche to say this but the late Sheldon Brown's website (
http://sheldonbrown.com/) is a great place to learn almost everything you need to know about bikes. There is a bike glossary on his site with practical definitions of most every term you would run into in cycling. Do a lot of reading and get familiar with how bikes work, parts, repairs, etc. That will help you know what you need when you do go to get a bike to tour on. Knowing how to work on your own bike is I feel very important for making the right choices in buying a bike.
Good luck and have fun