A standard procedure for book promotion is mailing copies of your book out for book reviews. You can conduct a search on Google for “freelance book reviewers” to find reviewers, sometimes categorized by subject. Freelance reviewers often have writing assignments for larger media venues and it is often more successful to contact them directly than through larger magazines or newspapers.
As you seek out reviews on your own, remember that some magazines are more inclined to only review books that have not yet been published while others will want the chance to review it immediately after publication, so it is in your best interest to start this part of the process right away.
If you are serious about getting book reviews, you should send out copies to these publications sooner rather than later.
Also, ask yourself what the specific market is for YOUR book. Once you know your answer, ask yourself what sort of magazines, newspapers, websites, or periodicals those people read. The more you narrow down your audience, the more efficient and cost effective your book marketing campaign will be. Send a review copy to every magazine, newspaper, website, blog, or newsletter your potential audience may read.
When you send out a book for review, always include a complimentary copy of the book, a professional cover letter, and a sales sheet and/or a press release.
To get you started, here is contact information for a syndicated book reviewer who is known to write reviews for self published books:
Gary Roen
Syndicated Reviewer
1600 Hull Circle
Orlando, FL 32806
Self Publishing Advisor 
Gary,
Thankfully, there are many outlets for reviews of self-published books, as there are free PR media online resources to announce the publication of a title.
However, careful selection and early advance notification on a book publication date is critical. It is more common with self-publication for reviews to happen on or after the book publication date. This, though, is not the norm with mainstream publishing, where galleys (early proofs) and ARC’s (advance review copies) can be sent out to media review sources weeks, sometimes a couple of months before publication.
There has long been an on-going argument about how effective book reviews are to actual sales. Certainly, I think self-published books rely far more on review exposure than mainstream publishing.
Hi Gary,
Long time, no see. I have a book out. Need to talk to you. (407) 227-7599.
thanks,
Penny
Hi Penny,
I’m not sure Gary will see this post, since he was only referenced, but not the actual author.
Congratulations on your work. Where is your book available, or where were you published? Perhaps I help point you down some productive paths.
Karl