John, I don't know much about this, but many authors put up new books on smashwords.com for a few days for free. Then Amazon.com matches the free price and they appear on Ereaderiq and various other places that gets you some free visuals of your covers, free pub. And if you're lucky (and the number of free books that day is small), you get listed on the daily free books message from Happy Reader Joyce in these discussion forums. Then if enough people download your book, it gets in the "top 100 free books listing" on the main kindle page. When it goes off free, it may convert (by virtue of its "free" sales") though now it is not a free book into the "top 100 paid ebooks" on Amazons Kindle page and you get listed right next to Stephen King et al. This may drive paid sales for you (or it may not). You probably want to ask about all this on Meet the authors forum (see link about) as I am not an author. they will clue you into all this stuff.

Might make more sense for you to do a few free a day rather than all at once, to keep your name up so more people have a chance to see it over several days.