If I’m looking for (history) book reviews, are there legitimate or, otherwise, well-known blogs or sites that one can check out?
As a new “fan” of History I’d like to be able to filter out books that may be too skewed in an ideological direction or watered down in a pop-History sense.
You don't specify a particular time period. For the ancient world, not to toot my own horn, Ancient World Magazine publishes reviews of books (among other things) that you can check out. There's also the Bryn Mawr Classical Review.