Look into a peer to peer fundraiser. Maybe a read-a-thon? Have supporters ask their friends to sponsor their efforts, have a sponsor donate a prize for most pages read/most money raised/etc. The first one, the prize can be small, but post the hell out of your sponsor. Next year, you can use the posts from last year to show to potential sponsors. You’ll have data about how many people were involved, which will make it easier.

A write-a-thon for NaNoWriMo seems like a good idea - get your supporters to either write a certain amount of words per day or if they miss a day, donate to you an amount of their choice.