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.
Mastered and Commanded (Pirates - First Time Gay Feminization Menage Romance)
Hoopstars and Two Cute Guy College Dorm Mates Get Transformed Into Trannies: Interracial Gay Sissification Transformation Transgender Adult Erotic Fiction
Naughty Alchemist: Gender Swap Fantasy Collection
The Ancient Mystical Egyptian Gender Switching Panties (Gender Swap / Transformation)
From He to She (Gender Switch / Transformation)
Transformed Into a Bride (Transformed #11)
Attached To His Rear: Taboo Punishment Pegging
Hoopstars Volume 5 - How To Be A White Tranny Slut To A Whole Gang Of Black Guys: Tgirl Alhena Adams Gets Owned By A Black Gang (Forced Interracial Transgender Erotic Fiction)