We went in May and did almost an excursion a day. We really enjoyed them all, even though they were expensive but we knew that ahead of time and Norway is expensive anyways. What I really found helpful was the daily talk. The excursion manager would give us some history of the next ports and would tell us about the excursion. As far as booking them, I looked at each one before we left to see if there were limits to how many could go and if it was a low number AND it was one we didn’t want to miss I booked it before we left. The majority of our excursions though were booked on board and I would definitely recommend that. It worked well for us.