Some years ago I started looking at conservative review sites here and there to look for potential concerns, so I wouldn't be taken by surprise.
I was happy when Common Sense Media came around -- they tell you about potential concerns in what I think is an appropriate "so-you-know" tone. They give ratings in categories, as well as an overview and in-detail information about the categories like sex, language, consumerism, violence, educational value, etc.
I can't always double-check every title, but it's good to know it's there.
I also appreciate the heads-up in emails on this list-serv.
Thanks!