A patron shared with me a few sites where she learns about free
ebooks. She signed up for the newsletter, which e-mails freebie alerts
daily.
Pixel of Ink
is a blog that posts free or nearly free ebook deals. While many are
forgotten classics, there is a substantial number of new/popular titles
that just happen to be the "deal of the day".
Book Gorilla
is another freebie alert site that offers classics to contemporary
books. They allow you to search/sort by genre and by price (for those
that are not free).