Let's see, you have cycling experience and outdoors/camping experience. I am assuming you have the camping gear also. Do you have panniers already? All you need are some panniers and the desire.
Do you know how to make basic repair to a bike?
I'd recommend a weekend trip to test out the bike, equipment, and yourself. You'll learn what works and what doesn't for you by doing that. Since you have outdoors experience I guess you have a good idea of what you need to take for your comfort level.
Other than that, just do some longer weekend rides leading up to the tour and go!
Any other specific questions let us know!