This thread is moving fast, but a word of waring for anyone...
Buying tickets was easy (pick type, enter payment info). BUT after I bought tickets the website just sat at the confirmation page. I had assumed I'd automatically been kicked to a reservation page, but I wasn't. So for a moment I didn't know what to do.
I went back to the DL main page, clicked the reservation link, and fortunately it knew I had tickets. Also, this might be obvious, but I realized only at the last minute that I had to reserve each date of my two day tickets individually.