Lots of folks swear on LibraryThing for digital giveaways. It's easy enough to do a 100-book (or 50, or 20) giveaway. The return looks to be about 10% reviews, which is a heckuva lot higher than through random sales. I just did one and am waiting to see how it goes. As far as listing your freebie, Ereader News Today, Pixel of Ink, and Freebooksy are three good ones. Some more resources:
http://www.indiebookslist.com/kdp-select-submission-form/
http://www.pixelofink.com/sfkb/
http://ereadernewstoday.com/ent-free-book-submissions/
Books on the Knob: https://docs.google.com/spreadsheet/viewform?formkey=dHI3UVVZdTZkWUo3d2w3aDExbXk5MEE6MQ#gid=0
freebooksy
http://bargainebookhunter.com/feature-your-book/
http://flurriesofwords.blogspot.com/
http://www.thatbookplace.com/free-promo-submissions/
http://freekindlefiction.blogspot.com/p/tell-us-about-free-books.html
http://www.orangeberrybooktours.com/2012/06/orangeberry-free-me.html
http://authormarketingclub.com/members/announce-your-free-book/
http://www.ereaderiq.com/free/
http://tracker.kindlenationdaily.com/
http://thekindledailydeal.com/contact.cfm
http://bookgoodies.com/
http://the-cheap.net/authors/free-promotion-opportunities/share-your-deal/
http://onehundredfreebooks.com/contact.html
http://authormarketingclub.com/members/submit-your-book/
http://www.mediabistro.com/galleycat/free-ebook-promotion_b52130
Book review blogs are a good bet for actually getting your book reviewed, but many have long waiting lists, small followings and may/may not post to Amazon.
Ultimately, promote judiciously and have a lot of patience. And read a lot of the posts here. Great stuff.
http://www.indiebookslist.com/kdp-select-submission-form/
http://www.pixelofink.com/sfkb/
http://ereadernewstoday.com/ent-free-book-submissions/
Books on the Knob: https://docs.google.com/spreadsheet/viewform?formkey=dHI3UVVZdTZkWUo3d2w3aDExbXk5MEE6MQ#gid=0
freebooksy
http://bargainebookhunter.com/feature-your-book/
http://flurriesofwords.blogspot.com/
http://www.thatbookplace.com/free-promo-submissions/
http://freekindlefiction.blogspot.com/p/tell-us-about-free-books.html
http://www.orangeberrybooktours.com/2012/06/orangeberry-free-me.html
http://authormarketingclub.com/members/announce-your-free-book/
http://www.ereaderiq.com/free/
http://tracker.kindlenationdaily.com/
http://thekindledailydeal.com/contact.cfm
http://bookgoodies.com/
http://the-cheap.net/authors/free-promotion-opportunities/share-your-deal/
http://onehundredfreebooks.com/contact.html
http://authormarketingclub.com/members/submit-your-book/
http://www.mediabistro.com/galleycat/free-ebook-promotion_b52130
Book review blogs are a good bet for actually getting your book reviewed, but many have long waiting lists, small followings and may/may not post to Amazon.
Ultimately, promote judiciously and have a lot of patience. And read a lot of the posts here. Great stuff.