Are book reviews peer-reviewed? Are news articles peer-reviewed?
Book reviews, opinion pieces, and news articles are generally not peer reviewed.  That's not to say there's no review at all: editors read and approve these contributions, and they may request changes before publication if they feel it is necessary.  It's even possible that an editor would ask for an opinion from a third party.  However, peer review (by an external expert) is not a standard practice for these sorts of articles.


  Books are not peer reviewed in general.


Books can be an intermediate case.  Acquisitions editors often solicit external reviews of book proposals or manuscripts, to decide which ones to accept and how they should be revised.  However, you are right that the level of review is generally not as comprehensive or detailed as it is for journal articles.