Columbine is interesting to me (and probably most people of my generation) because I was IN high school when it happened. I was a sophomore when the shit went down. I don't recall hearing much about it at school that day, but when I got home, my girlfriend and I watched the coverage on TV in my bedroom and it was captivating.
Nationwide, it put the fear of god into schools and the change at my school was immediate: zero-tolerance rules and crackdowns on trenchcoats and people who looked weird. One of the biggest rumors of the Columbine shooting is that it was carried out by loner goth kids. I wasn't one of those people, but I did run in the circles of people similar. All of my friends were the kids who wore black and had wallet chains and long hair and listened to Korn and whatnot. So immediately, I began to see my friends being harassed and judged. Trenchcoats were forbidden at school and anyone who dared wear one was suspended. The crackdown was ridiculous and it was all based on the myths and half-truths coming out of Columbine.
Myths that turned out to be complete falsehoods in most cases. Dave Cullen's Columbine is widely regarded as the most comprehensive account of the entire tragedy, from planning stages to anniversary memorials and all the dead bodies, shattered families, and lawsuits in between. Based on interviews, testimony, evidence, and full access to the Basement Tapes and Eric and Dylan's journals, the books covers almost every concievable angle of the shooting. The only thing that would have made the book better or more informative would be access to the parents of both shooters, but the Harris and Klebold families have refused to speak publicly in the 11 years since the shooting.
Every detail of the shooting itself, from things the killers said during the murders to the order in which they did things, how each person was killed, who survived and how they survived, and all the details in between are recreated based on extensive eyewitness accounts and it's fuckin' gripping man. You forget that these are real people and it begins to feel like you're reading a thriller novel. That's a testiment to how well researched and written the book is.
If you have even a passing interest in the events of Columbine, I highly suggest this book. Not only is every detail presented clearly, it does a great job of debunking nearly every myth that came out of the tragedy, many of which still live on today.