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.
Code Name: Swagmella
Gender Swap Soda Pop: No More Soft Drinks (Gender Swap Transformation Erotica)
The FemDom Nurse: Domination Sessions In My Dungeon (Female Domination)
Brought to his Knees: The Submissive Male Series - Part 5 (Femdom Story)
Transsexual Love Story 3 - Lori's New Girlfriend (Transgender Transbian Cougar Romance)
Devil Dudes (Gay Supernatural Transformation Erotica)
Junk: A Gay Transgender Holiday Romance Novelette (Vintage Toys for Lucky Boys Book 2)
IRON MAIDEN a Novel