@Kirin Rosenbaum
In order to receive a donation you simply just be an active participant in this thread. If you stek a look at the rules section,you will find the "wishful thinking" rule. This is simply the one time that a single user can post the words "wishful thinking" and make a plea for the items that they want. If a user does post this, it is likely that some or all of the items on their wishful thinking plea. Other than that there are small donations, such as if you want to order some food or drink item from snack attack.
There is no specific time, but when a donation is sent it can take a minute or an hour, depending of the user is online or not. Once a donation has been sent the donee will get pinged to the exchange thread to check their trades.
Does that answer your question dear?