Way back when, Alt.Fan.Furry regularly published a big check-list of things to take with you to a convention. While it will be impossible to cover everything for everyone, there should be common items (soap, passport, tickets, soap, map, soap...) and possibly some items that first timers might not thing of. Like poaster tubes, sturdy cardboard boxes to protect conswag on the way home, power strips, etc.
A more general version of the 'introduction to german culture' someone mentioned at the feedback meeting.
If the forum was able to come up with a reasonable list (which would be another topic elsewhere) would eurofurence be able to send it round to everyone one month before the convention?