http://www.nbtda.com National Bicycle Tour Directors Association
http://www.adv-cycling.org
http://www.bicycletour.com
You will be able to find a tour to fit your needs/desires/location/schedule on one of the above sites. I am a member of the NBTDA and Adventure Cycling so I listed them first :>) IMO supported tours are an excellent way to determine if you like touring.
There are so many fantastic tours it is very dificult to decide......
Good Luck and Happy Touring.
Sorry for double reply....I mistyped http in
http://www.nbtda.com link