Here is part one of what may or may not become a series. The first knitter that everyone should know is the absolute most influential knitter probably ever, but at least in recent history: Elizabeth Zimmerman.
Elizabeth Zimmerman is credited with:
--bringing Continental Knitting back to America after WWII when it had gone out of style as "too German"
--encouraging knitters to knit in the round on circular needles
--bringing the Aran sweater to America
--and many more innovative techniques that we take for granted today
Read about her at the very simple wiki page here: http://en.wikipedia.org/wiki/Elizabeth_Zimmermann
And read this great Vogue Knitting Tribute to her here: http://www.vogueknitting.com/node/485
Or do your own search for her and her wonderful books.
Happy knitting and crocheting!