Dan,

To get advanced books I created an account at Netgalley (there are a couple of others, but I use Netgalley) and an account at Goodreads.  You have to agree to review books at Netgalley to receive advanced reader copies. Typically, the more books you review and post reviews of at places like Goodreads, the better selection of books you will be eligible for at Netgalley.   Of the books I have requested through Netgalley, only about three percent (out of close to eighty) have been declined and these have been books by the most very well-known of authors. 

Netgalley also likes reviews of books posted to a person's personal blog or website.

Also, Netgalley has a huge section of "Read now" books available for immediate download on the agreement of writing a review.

Oddly, through Goodreads, I was contacted by Sam Boush of MysteryandSuspense.com and asked if I would like to submit reviews through that website (non-paid - though there are plenty of book review sites that do pay) and through this relationship, he is able to get almost any book in the crime/true crime genres that I have asked for.