Depending on how much you like early blues, and how "authentic" you want to get, there are a number of early, great acoustic blues men that you should listen to, including: Robert Johnson, Huddie Leadbetter, Big Bill Broonzy (one of my all-time favorites), Blind Lemon Jefferson, Mississippi John Hurt, Son House, Howlin' Wolf, Willie Dixon (one of the most important influences on Mick Jagger, The Beatles, and other English "blues" groups of the 1960's), Sonny Terry and Brownie McGhee (Piedmont-style blues), Reverend Gary Davis, etc.
If you want to really delve into the blues, then you can get a lot of great information from the book by Bill Wyman titled "Bill Wyman's Blues Odyssey", which can be ordered from Amazon.com. Wyman is a former Rolling Stones member, and his book offers a very good introduction to the styles of blues and the great singers of each style (from Delta blues through modern urban blues).
If you want to really delve into the blues, then you can get a lot of great information from the book by Bill Wyman titled "Bill Wyman's Blues Odyssey", which can be ordered from Amazon.com. Wyman is a former Rolling Stones member, and his book offers a very good introduction to the styles of blues and the great singers of each style (from Delta blues through modern urban blues).