One can truly begin to understand the mystique of NASCAR after reading A Little Bit Sideways. Scott Huler's obvious love for the material really shines through. His writing transforms what, in lesser hands, could have been a dry and boring recitation of minute details into an interesting and compelling human interest story.
Read it. You won't be disappointed.
I've also read Shaun Assael's "Wide Open" and Paul Hemphill's "Wheels," which are similar in many ways but to my mind are both inferior. Assael's book seemed flat compared to Huler's, though fans of Dave Marcis and Bobby Hamilton may enjoy the coverage that those drivers receive in "Wide Open." Hemphill's book spent a lot of time on a thesis that I soon found repetitively handled: NASCAR was once the province of the Southern working man but is now corporate entertainment. Both Assael and Hemphill follow NASCAR for a whole season and seem to get bored with it. Huler stays focused on a shorter timespan to much better effect.
I've read some more technical approaches to NASCAR as well, and found that Huler almost always snuck the information in those books into "A Little Bit Sideways."
Although I find this the best introduction to NASCAR because it's so engaging to read and so comprehensive in the bargain, those who are interested in learning more about NASCAR might also try "NASCAR for Dummies" by Mark "Awesome!" Martin and Juliet Macur. That book lacks Huler's style and story-line, but it does have a lot of interesting information about NASCAR, including some tidbits on strategy and technology that I haven't seen elsewhere.
