In American English, left-handed people are called southpaws. Find out why here.
This article from the BBC (“The mystery of why left-handers are so much rarer”) tells us about the history of left-handedness, including some rather surprising statistics and the fact that the origin of the word “left” means “weak”. Statistics are different for people who are “left-eared” and “left-eyed”.
I’ve heard that in the past in Japan, children born left-handed were taught to become right-handed because of a social stigma or some superstition associated with lefthandedness. That doesn’t seem to be true anymore — I know lots of students who are left-handed.
You could also find out more about the symbolism of left/right in politics as a mini-research project.