Before I did my big tour through Europe, I went somewhere safe (Menorca) for a 10 day cycle trip to try everything out and see how it went, what I needed to get, what didn't work etc etc.
As a woman travelling on my own it gave me a lot of confidence!
For months before I left I spent a long time reading books/forums/internet to find out what everyone else took on a cycle tour and eventually narrowed it down to what suited me. I ended up with 4 panniers on my Dawes Sardar - what a fantastic bike!! LOVED every minute.