The Kentucky Derby is the first Saturday in May, which this year happens to fall on my birthday. That won't happen again until 2021.
The Louisville Courier-Journal of course has extensive coverage of the Kentucky Derby, including the 2010 Derby Briefing Book and the Horse Racing and local events blogs. The C-J's most-requested Derby recipes was originally published back in 1997: make sure to pick up a gallon of bourbon.
Events follow a schedule, and most everything in April and May are scheduled around Derby and the events scheduled around Derby. Thunder over Louisville, the fireworks and air show, is two weeks before Derby. BBC Brew Day is the week before Derby. The Great Steamboat Race is the Wednesday before Derby; the next day is the parade, and Oaks is on Friday.
Hunter S. Thompson wrote about the 1970 Derby (sort of) in "The Kentucky Derby Is Decadent and Depraved", and William Faulkner wrote on the '55 Derby in "Kentucky. May. Saturday." (h/t JH). Faulkner opens that piece by penning a paean to Kentucky as fine as you'll find. I'm queuing up the 1969 film of Faulkner's last book.
Anyhow, this post was intended to be about coverage of the race itself. The official sites are Oaks, Kentucky Derby, and Churchill Downs. Churchill owns TwinSpires.com for online wagering.
The New York Times' The Rail blog covers the Triple Crown. The 2009 edition was begun on April 20, and featured a blackberry-bourbon mint julep recipe. Steven D. Levitt often reveals his Derby picks at the Freakonomics blog (he was pretty hilariously wrong in 2009). The Baltimore Sun's horse coverage is more geared towards the Preakness. But it makes me think about how fantastic "The Wire" was.
Blood Horse has coverage of Triple Crown Mania, and CBS Sports and ESPN have horse racing feeds. Many horse racing sites like the Daily Racing Form are oriented towards subscribers, although there are some blogs ( 1 2 3 4 5 6 ). Wikipedia has a list of the winners back to Aristides.
The Kentucky Derby YouTube channel has including replay back to 2002. Here's the 2009 Derby, 2008 Derby and Oaks, 2007 Derby, 2006 Derby, and 2005 Derby, as well as things like Welcome to Louisville and Making your Mint Julep. I moved to Louisville in 2004, right after Smarty Jones won; so the first Derby I really paid attention to was won by Giacomo.