Lessons from my first tour, in Europe:

1. Do not make major component changes right before your trip. I had a mountain derailleur and cassette installed just before I left. The bike shop didn't tell me that in order to do that they seriously downgraded the rear rim---probably to a cheap road rim. In Europe spokes broke like crazy until I was forced to replace the entire wheel.

2. Make sure you test your other equipment before you leave---tent, mattress, sleeping bag, stove. I had total air mattress failure and had to spend 2 months sleeping on a 1/4" closed cell foam pad.

3. Research your destination as much as possible and have a detailed itinerary. I spent half of my trip biking through heavy industrial areas in Holland and Germany. No, Europe is not beautiful everywhere.

4. Camping in people's backyards is rewarding and safe, compared to stealth camping.