A book I'd recommend for anyone who wants to improve the communication in their relationships -- romantic or otherwise -- to help resolve any kind of conflict,

A book I'd recommend for anyone who wants to improve the communication in their relationships -- romantic or otherwise -- to help resolve any kind of conflict, is "Nonviolent Communication" by Marshall Rosenberg. The ideas are very simple, almost obvious, but his exposition is brilliant and really reaches deep into the human experience. He makes a convincing argument for how our learned behaviours have led to widespread inability to effectively resolve conflict, and he gives a straightforward model for overcoming this.