John Piper's books have blessed my family, too.  Thank you for the website.
 
Another good author that deals with legalism is Philip Yancey.  His book called Soul Survivor is about his struggles to separate the legalism which he grew up with from the Truth that is in the Lord.  Don't get me wrong, we are not talking about a conservative or Bible believing church.  He is talking about a church situation that was all rules and taught wrong doctrine, especially the superiority of white people.
 
Brenda N