IMO, here is an interesting book review which contains much about Rush: click here. Here's the last paragraph:
This book should be required reading for every registered Republican. I think perhaps Rush Limbaugh is a Big Fat Idiot (and Other Observations) should even be an official textbook for America's high schools and colleges. I have theory that most people start out as "knee-jerk" liberals or the conservative equivalent. These people don't truly understand issues. If they are never exposed to anything but ten-second sound-bites, they remain uninformed. But when someone comes along who adds depth to these people's knowledge on issues, they become informed and more moderate in their views. This country needs lots more informed moderates, and Al's book might be a good tool to help meet that need. What Limbaugh claims to do for "knee-jerk liberals", Al Franken does for the conservative equivalent. I highly recommend this book, especially if you want to be more informed about the political landscape and need a good laugh at the same time.
As for Limbaugh being a racist, these are direct quotes, emphasis is mine:
In the early 70's, Limbaugh once told a black caller: >B>"Take that bone out of your nose and call me back." A decade ago, after becoming nationally syndicated, he mused on the air: "Have you ever noticed how all composite pictures of wanted criminals resemble Jesse Jackson?"
In 1992, on his now-defunct TV show, Limbaugh expressed his ire when Spike Lee urged that black schoolchildren get off from school to see his film Malcolm X: "Spike, if you're going to do that, let's complete the education experience. You should tell them that they should loot the theater, and then blow it up on their way out."
In a similar vein, here is Limbaugh's mocking take on the NAACP, a group with a ninety-year commitment to nonviolence: "The NAACP should have riot rehearsal. They should get a liquor store and practice robberies."