Do a Google search for websites and book bloggers who review your genre.
Look for trade magazines and contact other authors in your genre.
Midwest Book Reviews is a major reviewer who accepts self-published books.
Sites that list reviewers -
EBook Crossroads - database of reviewers, includign those for audio books.
FSB Media - very large database of book bloggers, search by genre.
Book Blogger List - database of book bloggers, search by genre.
Book Review Blogs - database of book bloggers, search by genre.
Step by Step Self Publishing - list of reviewers for self-published books.
The Indie View - list of reviewers for self-published books.
Some tips when sending out review copies:
Send out books before the publication date if at all possible.
Include a review slip on the inside of the cover flap that lists title, author, ISBN, publisher information, genre, formats, page count, and distributors/wholesalers.
Query first before submitting an E-book as an attachment.
Budget! How many print review copies can you afford to send?
Set up a Google Alert for your name and book title to catch online reviews.
Avoid paying for a review.