Johnny Winter - "Be Careful With A Fool"
http://www.youtube.com/watch?v=HxOiiqleJuI
That's the only one I need to offer by Johnny. A person either gets it on the first listen, or they don't.
Enjoy the journey! You'll spend a lifetime discovering new artists every month, so you always have something good in your future no matter what else happens.
Martin took the time to provide you with excellent links as a gateway; he definitely deserves best answer.
Son House
Charley Patton
Robert Johnson
Blind Willie McTell
John Lee Hooker
Leadbelly
Mississipi Sheiks
Blind Boy Fuller
Elmore James
Mississippi John Hurt
Fats Domino
Blind Lemon Jefferson
BB King
Howlin' Wolf
Muddy Waters
Junior Kimbrough
Seasick Steve
RL Burnside
Buddy Holly
Tom Waits
Jack White
Mike Bloomfield eric clapton( bluesbreakers,cream,dominos,) freddie, albert, bb king, peter green( that is who gary moors les paul actully belonged to also founded fleetwood mac befor they got all gay), and buddy guy