I don't read reviews. First of all, reviews on
Amazon can be a popularity contest. I know of many writers who get all their friends to rate their book 5 stars. I once made the mistake of buying a book that had over 100 5-star reviews, and the book was horrendously bad. I then realized the writer must have spent more time creating sock-puppet identities to review her book, than she spent writing the actual book.
I don't really get into professional reviews either-- I only read them to find out more about what the book is about. Because even professional reviews are subjective-- it's not a panel of professionals reading and reviewing, it's just one person's opinion.
I don't think Goodreads is accurate, either-- too many people reviewing a book based on whether they like the cover or the title or the sound of the author's name.
Mostly, I check to see whether the description is something that interests me, and then I check who the publisher is (I'm a bit of a snob that way). Enjoyment of a book is COMPLETELY SUBJECTIVE. No one person or group of people should be able to tell you what you will like or dislike. Read the description of a book, and decide based on whether that sounds interesting to you. If you go by reviews, you may be missing out on something you might really have liked.
Also-- I think "free" books are free for a reason. A lot of times, you get what you pay for. If I wanted to read free stuff, I could read my first-grader's book reports. It amazes me that people will tip a coffee barista a dollar for a coffee that took 3 minutes to make, but balk at paying a few more dollars for a book it took an author a year to write!