Fresnel equation specular/diffuse/refraction etc...

I would like to use the Fresnel reflectance equation to control the materials in my raytracer. Especially for rendering water. Can someone explain a system using the Fresnel equation and how to relate specularity, diffuse, refraction etc... I would also like the shader to be able to be used in a Monte-Carlo path-tracer so I also need the probability of different events at an intersection point. I.e specular reflection or diffuse reflection or refraction or... Cheers,