I am a fantasy-fiction reader with a Kindle who frequently trawls through the Kindle store for new things to read - your target audience, I guess - and I can say I'm MUCH more likely to try an unknown author on a whim if they have at least some good reviews on Amazon, and if they are offering a book at a cheap price. (Cheap for me on the Kindle is $0 - $2.99.) I don't think authors should work for free, but it's like radio and Spotify for musicians - people need to experience your work for free (or nearly free) before they'll pay full price for it.

Maybe you could write a great short story in your world and/or with your main characters, and give it away on Amazon for free, as a way to introduce people to your work, and then charge a fair price for the novel. You can even have a teaser on the last page... "Find out what happens to [best character] after [intriguing event] in [novel title] available in Winter 2012!"

Get friends and family to write good reviews and post them on Amazon for you. As many as you can without it looking fake (e.g. don't have them all post 5-star reviews the same week you put it up for sale... that is not believable to readers). And don't just do generic "this book is awesome" but have them put something specific ("I really liked the unusual portrayal of dragons" etc.). Have the reviewers compare your work to other well-known writers ("Neil Gaiman meets J.K. Rowling on steroids!") so that readers will think "Oh, I like those books, I'll probably like this too."

But all of that depends on someone actually landing on your Amazon page in the first place. The first battle in the war is getting people to go to that page, and for that you need either paid advertising or word of mouth or a ton of luck (or all three).

A friend of mine self-published a book a couple of years ago and has sold thousands of copies through advertising and working really really hard at networking and getting the word out - Facebook, twitter, LinkedIn, youtube, friends, co-workers, etc...