Hey, looks at this. Eraserhead is getting it's first theatrical release in Russia (along with a few other David Lynch titles).
It's my favorite David Lynch movie, and one of my favorites in general. But I'm not sure how I'd prepare the audience. It's spooky, but isn't a horror film. It's funny, but is definitely not a comedy. It's surreal, but does follow a plot (of sorts).
Just go in and be open to the experience. And don't treat it like Rocky Horror or some other midnight movie--there may be an audience around you, but this is a very personal film that individuals have to experience in their own way.