There are numerous good books on John Adams. Among them are Ellis’s _Passionate Sage_ and Ferling’s _John Adams_. If you care about Adams as political thinker, C. Bradley Thompson’s _John Adams and the Spirit of Liberty_ is outstanding. Here’s my review of it:
McCullough’s Adams pulls off the astounding feat of considering Adams’s life in great detail without saying much of anything about his political thought. If for no other reason, that’s a sufficient cause to skip it.