@Batman. Just like Stark 1 said, I'm gonna quote him again.
basically .
if youre the one donating youll get an automated PM with details on your donation . after that you add a GM to the PM which will be on the left hand side .
now if you want to buy something from the item donation list you can talk to a gm in the pm about that . if you'd like to trade with someone all you have to do is add that person to the PM also along with the GM of course , stating that you are giving that person said DTS (donation TicketS)