So, the donations are starting to come in, great news!
Donors like to feel that their contribution mattered so why not show your appreciation by leaving a personal message of thanks against each donation? As well as being emailed to the donor, your responses will appear on the page and show other potential donors that you're a nice person.
You can also set up a custom message to be sent out with each donation receipt. This is a more general message of thanks as it's the same for everyone. It can be useful for both thanking donors and asking them to help by sharing your page, or giving them links to other information.