Ayn Rand

So I've been hearing a lot about Ayn Rand lately, and I have come to realize that I know hardly anything at all about her.  NPR is talking about her, House Republican budget chairman Paul Ryan makes sure all his staff has read her most famous novel, the Guardian thinks Tea Partiers are taking her out of context, and a movie of her novel Atlas Shrugged is out.  And yet I don't know the first thing about her life, or objectivism, or anything about her.  I didn't have any of her novels as required reading in high school (you decide whether that makes me lucky or deprived).  So yesterday I picked up an introduction to Ayn Rand book, which I'll be eager to read and report on.  For those who have read her works, what's the big deal?