I'm coming from Amsterdam, one and a half hour trainride to Emmerich where my hotel is, from there it's 15 minutes to Haldern. Think the closest airport is Düsseldorf, from there you can take a direct train.
Festival is on walking distance (approx. 15 minutes) from the village, lots of people walking into the village in the morning for breakfast/shopping. Also few bands play in the village (Pop bar, church) during the festival.
Most people go camping, all Haldern hotels seem to be fully booked for ages. It's quite old school which I actually like. Chips, curry wurst and a few other other stalls, but no hipster foodtrucks. It's basically only about the music. Still don't understand how such a small village can book all these great acts every year, but happy to go there again.
Hope this helps.