Dragonboy - Project Gutenberg

I'm a page away from completion of The Dragonboy of Regnaville - a short story based on one of the characters from The Dragonscale Blade.  The idea for writing these short stories was partly for me to find out a bit more about the backgrounds of these characters.  ( I have a queue of dodgy characters waiting to be written about and they're in danger of turning into an ugly mob!)  But also I was hoping to give the stories away for free.  With Amazon, that's only possible for 5 days out of 90.  I've not had the time to explore other outlets, but I now know that Project Gutenberg specialises in giving away free books.  So that might be my first option.  If any of you have had experience of Gutenberg or any other ebook outlets, I would very much appreciate your comments.  Thanks.