OK, if you have no clue what Civil War is, then this probably won't be of much interest. In a nutshell, during a fight between superheroes and supervillians near a school, one of the villians causes a huge explosion that kills a lot of people including dozens of children. THis polarizes the nation and the gov't passes the Superhero Registration Act. This review
of a recent Spider-Man tie-in shows some of the big flaws behind what could have been a fascinating storyline.
There have been some Civil War tie-ins and books that I've liked, mostly the Front Line" title that has been following two reporters who in turn are following opposite "sides" of Civil War. There has also been some of the worst writing I've seen in a long time, stuff I'm amazed that the editiors actually allowed to see print.