How to get into Hip Hop music?

I'm sorry, I have to admit that I have not looked too favorably upon hip hop music in the past, however, I am not gaining some interest in the genre after listening to a few songs on an iPod. I'm 21 years old, and I have not exposed myself to rap or hip hop (are they even the same thing?) too much during my life. The question is though, where does one start? How can I refine my tastes in hip hop or rap, and become one of those in the know? I mainly listen to jazz, blues, clical, country, and some rock and roll music from back in the day (1950s, some 1960s). So, with my tastes being the way they are, is there a particular sub-genre or artists I may like?