I vs. me? Which one?

He vs. him? I vs. me? She vs. her? Who vs. Whom? Which one? To find and understand the answer, I would view Lessons 136-140.
http://www.dailygrammar.com/Lesson-136-Pronouns.htm
http://www.dailygrammar.com/Lesson-137-Pronouns.htm
http://www.dailygrammar.com/Lesson-138-Pronouns.htm
http://www.dailygrammar.com/Lesson-139-Pronouns.htm
http://www.dailygrammar.com/Lesson-140-Pronouns.htm
http://www.dailygrammar.com/Quiz-136-140-Pronouns.htm