Welcome to the blues, a truly deep flavor of music. To get you started on your path to Bluesville, here is the least you need to know.
Origin
Blues has been around since the slave trading 1800's. It was a means of communication for slaves of the time.
Types
There are four main types of blues: Delta Blues, Chicago Blues, Texas Blues, and Blues Rock. More modern forms of blues include East Coast Blues, Harmonica Blues, Modern Electric Blues. A more detailed explanation of the main and more modern types is available here.
Blues pioneers
Pioneers of blues include Charlie Patton (Delta Blues), Memphis Minnie (Chicago Blues), Muddy Waters (Chicago Blues), Blind Lemon Jefferson (Texas Blues), Jimi Hendrix (Blues Rock), and The Rolling Stones (Blues Rock). A quick Google of these names will get you far more information than you will ever want.
Happy blues