As NAEA is not an accrediting agency or anything, they can't award certificates and the like. To help with this, in your registration packet you do get a letter of attendance.
Also, every district and state is different in what they require. Some require signatures from session presenters, attach session info to requests, etc.. Find out what your district/state department requires before you leave. I have to record hours in our district's electronic portfolio system and verify attendance
See you in Seattle!!
(middle school in Oregon)