69 firebird wiring problem
 

i have a problem with my 69 firebird. its has the 6cyl. OHC 1bbl. the one thing i dont understand at all is wiring and electronics and that finally got me. me and my friend hooked up the general lee horn in my car and its been messed up since then after she SWORE she knew what she was doing my battery died, my fuses are popping, my brake lights and turn signals in the back dont work and im so lost on what to do. does ANYONE have any suggestions. i printed out a wiring diagram and its jsut pretty colors and lines to me. i dont understand this stuff. someone help please;)