read it, it's very cool
it's like a novel, but instead of words only like a normal book, it has visual and sound effects, sometimes has voice.
and sometimes they let u choose between several options, and the story will go depends on those options u made.
For a starter, I'd recommend Fate Stay Night or Tsukihime, though they have adult scenes, but they are rated as one of the top action/romance Visual Novel. If u prefer a non-adult, mystery one I recommend Ever 17. Or a soft, romantic one like Clannad is good.
I'm doing a Forum-based Fate/Stay Night, so if u don't mind read 54 pages of prologues, I can create one thread for u.