Curled Up With a Good Book is a website full of book reviews from many different genres. New reviews are added frequently and there's a searchable archive. This site also provides links to many author websites. Just the thing if you need to know which book comes next in a series.
Curled up has a kids' site too. Curled Up with a Good Kid's Book has reviews of everything from board books to young adult titles.
Link courtesy of Kids Lit.