Hi All -
I am at the task in my checklist to research getting the marriage license! The DC court page was pretty good but left me with a few questions. I then found this site/step by step guide (link below). For those of you getting married in DC - this looks to be the most helpful information and up to date.
http://washington.org/visiting/experience-dc/pride-in-dc/glbt-marriage Wanted to share and hope it helps!