The documents I took were...
(for me and my wife)
1. Approval Notice (courtesy copy)
2. I-94s
3. Pictures, 2 each
4. Passports
5. EADs
6. Advance Parole
The officer did not ask for advance parole or EADs, I guess they will be trophies! The notice said I should go to the Seattle office but Bellevue is much closer, easier though it only opens Tuesday and Thursday. The officer was very cool, pulled up our records on his computer, got our fingerprints, signatures, I-89 forms.
The biggest anti-climax is the stamp - it is just 4-5 lines of text, nothing fancy. The offices scribbles a few lines including A# etc and that\'s it!! Took about 15 minutes.