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.
Help! I'm Trapped in My Sister's Body
Slippery Descent (Alex's Adventures in Wonderlust)
German Fräulein Max: Four Episodes from a Cuckold´s Married Life (Edition Feminized Cuckold)
The Male Bridesmaid : Chastity, Forced Feminization and Female Domination.
D'Nine Vol.01: #01 - #03
Stealth (Gender Transformation Erotica) (Dating Kyle Trilogy)
Secret (Gender Transformation Erotica) (Dating Kyle Trilogy)
Discovering My Identity: Five Fictional Stories of FTMs
I Woke Up a Man!
FUN WITH DICK AND CUNT (Thrillerotica)
Diary of Ally Doorie: Erotic Short Stories Exploring Sexuality to the fullest (The Erotic Tales Tanya and Ally)