Update: Here's also a nice julep recipe from the awesomely named Wasabi Bratwurst. It is very classic and traditional.
A Mint Julep is one of those things, like czarnina, that sounds lovely, but the name masks its true contents.
The word "bourbon" is nowhere in the title of the drink, but bourbon is what makes up 99% of a julep. There is mint, to be sure, but it's a spring or two, muddled around in the bottom of a glass. Depending on your recipe, sugar, simple syrup, or soda water is then added to taste, and it's served in a shiny silver cup.
Clearly, the quality of bourbon that goes into a mint julep is key. Use top-shelf stuff for this if you even want to attempt it, folks, especially if you are not normally a bourbon drinker.
My friend, who dutifully drinks one Mint Julep a year, on her High Holy Day, the Kentucky Derby, uses Woodford Reserve bourbon. It's good stuff, but pricey.
If you want to try a mint julep, here's some recipes for you.
Becky's Mint Julep recipe at Blacktype Blog. She'll have this up before post time tomorrow.
Alton Brown's Mint Julep. He's a southern boy, so he should know his stuff.
Old Mr Boston's Mint Julep. A recipe from a classic tome of mixology.
The Official Mint Julep. From the Kentucky Derby Web Site.
Now, here's something strange. The official sipping bourbon of the Kentucky Derby is Woodford Reserve. But the official bourbon for the mint julep is Early Times. I've had juleps made with the former, but not the latter, so I can't speak to the quality of the Early Times, so I still recommend going with the best stuff you can afford, at least to start. It'll last you for at least a half a dozen Derby Days.