I am approaching to Beilinson Conjecture and after studynig some properties of the Deligne-Beilinson cohomology, I want to understand the regulator maps. But I don't know anything about K-theory and I would like to understand the necessary background. Is there any reference or some reasonable "chain" of references to follow to understand the construction of regulator? Secondly, I would like to clearly understand the relation between this regulator and L-functions. Can someone help me? Thanks you!