I investigated and made a list of all the HF and general book reviewers I could locate on the web that seemed to cover my time period/genre and sent them a query letter with a description of the book asking if they wanted to review it. Mine was print and ebook, so I gave the reviewer a choice as to format. You'll want to check out the submission/review guidelines; some don't accept ebooks and some don't accept self/indie published. If you go to
my blog, I have a list of reviewers on the right. That should get you started, but more are popping up everyday.
Another good "soft marketing" tool is to offer to guest blog on a History/HF blog. (Again, check out my blog roll to start, each blog will have their own blog roll, you can branch out.) Investigate the sites for compatibility, contact the owner and pitch a proposal. Many sites will be grateful for free relevant, content. It should be about a topic related to your book, but not a review of your book...some interesting piece of research or something in the current news related to your book. The introduction can then say "Laura Gill, author of
The Young Lion" with links to your website or sell page.
I agree that the Amazon boards are lousy with spam and most people don't pay attention to them anymore. Goodreads and LibraryThing (also listed on my blog) are great. You can offer free copies for reviews on LibraryThing through their Member's Giveaway program. But I'd recommend going to the
HobNob with Authors group first, browse, participate, then offer your book for reviews on that thread.
Marketing is the bane of our existence. It sucks our time and requires skills authors usually are not good at, but it must be done! Good luck.