So, there are a few things you need to do in order to run a book review blog. The list below should help out anyone new to blogging or who thinks their blog could use some improvement.
First, start a blog. I happen to be partial to WordPress.
Second, read a book. Preferably nothing by Ayn Rand, but that’s just me.
Next, review the book with a clear rating, either through a number of stars (which you explain the meaning of somewhere) or simply whether or not you would recommend it to other people.
Make it easy for authors to contact you. Either put your email address up or use a contact form thing on a designated contact page. If you run a book review blog, you can get free books. If you didn’t know that, you do now. It makes it easier for authors to spam tell you about their book they’re giving away for free. All they want in return is an honest review (and if they say “give me five stars or else” just ignore them).
A note: if you do want free books but not a certain genre, make that clear. Some authors will still ignore that, but if you don’t want to receive erotica and you’re under eighteen, usually stating that clearly will reduce the probability that authors will send requests to read their naughty things against your wishes. (However, I’m not sure if stating that you’re underage could welcome other safety problems as I’m 21 and haven’t thought about cyber security in a while… but yeah, don’t be Catfished by pedophiles. And stuff. I’m off topic.)
Finally, post book reviews regularly. It doesn’t have to be every day, but post often enough to make sure your blog looks active. This may also encourage you to read more, which is obviously a plus.