In reply to amikins: i was in the Jotunheimen in 06.
all the paths are marked with red paint, usually arrows every so often which makes path reading a breeze!
i'd get some decent boots as a lot of the paths were rocky.
it was blazing sunshine apart from two days when we were there for 2 weeks, we were wearing shorts pretty much all the time.
there will be a little bit of snow in some of the sheltered areas but not enough to need ice axe and crampons, we only came across one patch which we walked around with ease.
as for glacier walks, we went on a guided one, they provided basic 4 point solid 'crampons' that attached to pretty much every summer boot. however it will cost and might be worth taking the gear yourselves and doing your own glacier walk if you have the experience.
we took all our camping supplies with us on the ferry, took a van over with us and we took most of our food and only bought fresh meat and some veg out there as prices are massively high compared to england.
hope this helps!