my suggestions are many.u can prefer on twilight for both romance and actition. dan brown's books, especially 천사 and demons are a good choice.harry potter series. u may have read it. jeffrey archer's a prisoner of birth is also good.
책 to read... Hm... Well, I would recommend the Hunger Games, 또는 Divergent, 또는 Vampire Academy and then after that Bloodlines... PG, though... er, that would be hard with YA romance. Maybe Warriors (thats about cats) but its not that romantic... But there are some 사랑 conflicts, so that might be good. Twilight and all that is good too. Also, The Mortal Instruments ( my all time 가장 좋아하는 series) which is really good.