Crystal Grains

I'm about to make my second batch of beer (first time on my own). I decided to use a recipe I found in this book "Extreme Brewing" by Sam Calagione from Dogfish Head. It's a Brown Ale that looks easy to make. The recipe calls for 1/2 pound of "crystal-crushed specialty grain." Anyone have a pointer on what exactly I should get? I was looking online and saw lots of different crystal grains, like 40L, 60L, 90L, etc. What kind should I use for a brown ale? Thanks!

Any of those would probably work well. The lighter (40L) will be more of a sweet caramel flavor, the darker starts getting a little bit more bittersweet, a little more dark-fruit once you get up to 90L. Any of those flavors would be fine in a brown ale. I'd probably go with 60L, that's kind of a standard medium-crystal.

what does the "L" stand for?

"Lovibond." It's a measure of color, although with crystal malts different lovibonds also have different flavors. Lighter crystals (10L - 20L) add very little color, but also add very little flavor other than a sweetness. Darker crystals (90L - 120L) add more color, but even more important have a less direct sweetness, more of a bittersweetness, and have some raisen/plum/other "dark" fruit notes.

I like C60L to C90L in Browns.