We began by me telling the group what we would be doing, then we dived right in to the hands on exercise. Because there was a small number of people we were training, there was not much of a point in lecturing so we just divided up and helped 1 or 2 people individually. The results were very good in my opinion - having a one on one (or one on two) session like this really helped the students learn and also gave them the opportunity to steer the learning into something they were more interested in. For example, the two ladies I was helping were interested in emailing photos, so I showed them how Picasa had built in photo support using the Gmail accounts they had created in a previous session. They absolutely loved this
Overall I think the session went really well. The students seemed very interested in learning about photo management and were amazed at things we take for granted all the time (such as Picasa's red eye removal tool - which is pretty amazing). Doing this really gave me a new perspective on teaching.