LAST EDITED ON 24-Feb-10 AT 02:39 PM (PST)
I might add these recommendations:Get a GPS, car or handheld, have the PO text you the address. Tell them you use a GPS, it makes their life easier. (some will not text, but should give an address or an intersection over the phone). First time, allow time to get lost finding the right building, gate, door, etc. (you will) and spend sometime figuring out how the buildings are numbered and where the entry gates are before you call.
When you get there and call (5 minutes before appointment time), have something to write with and on. Don't try to remember codes and appt #s, you wont, especially the first nerve racking times. I use my iPhone notes for this. Repeat the info back to the PO to make sure you have them correct. I use a $20 VirginMobile (Walgreens) phone for hobby communications.