"Represent Yourself in Court" by Nolo Press, as well as any of Nolo's other books that interest you.
IMO learning some law is another level of taking charge of your own life and saying "hey world you ain't gonna fvck with me or screw me over." Just like going to the gym and getting all buff. Law knowledge is a strength you can use over and over again in all areas of life. My daughter told me not too long ago "My mom said she hopes you never take her to court, she is scared of you". Her mom(my real ex wife) and I are getting along fine now, no problems. At this time I have no plans or thoughts to take her to court. But just the idea she is scared of me from a legal perspective puts me in a pretty good place should issues ever come up in the future with our daughter.