"Do you read book reviews? Do you let them change your mind about reading/not reading a particular book?"
Yes. Being a bookaholic, I am usually tempted to buy whatever looks like in the bookstore. To hold myself back, I normally jot down the title and its author.
When the book lingers in my mind, I will checkout its reviews; normally from more than 5 readers. If it is good, I'll give it a shot. Else, I'll drop it from me list. ;)