Every Friday I take the initiative to search through thew newly free titles on Amazon, and to identify those that might be of interest to trans* readers, fans, and lovers. Even if you don't have a Kindle, you can still download the titles through one of Amazon's free reading applications, and covert it (if need be) with Calibre. I can tell you I do most of my reading on my iPad, using Kindle for iPad, and it works beautifully.
Please do be sure to check the price before downloading anything, though, as most freebies are limited time offers, and some are specific to certain regions.
Various TG Bundles from BJ Slippy
Discretionary Maid Service 1 - The Billionaire's Staff (Transsexual Shemale Erotica)
A Dress In The Closet: A Man Becomes a Sissy (Crossdressing, TG, bicurios, Gay Sex, Sissy)
Disciplining the Maid (Maid for Futas 1)(Futa-on-female, BDSM, spanking erotica)
Submissive Interview (Dominated by the Futa Boss 1)(Futa-on-female, Futa-on-futa, BDSM, Spanking Erotica)
SM, or How I Met My Girlfriend in a Queer Theatre (Transgender and Genderqueer Erotic Romance)
Another Gender Swap ...for Science! (feminization, gender swap, mmf)
Punished in Chastity: Femdom, whipping, and male chastity (Femdom Slave Book 2)
THE DELICATE LITTLE SISSY MAN
Save the Date (Genderswap Erotica)
The Bid of a Lifetime