Karen,
I have found it helpful to know where the organs are.....I purchased a book that has good illustrations. Master Lin does encourage his students to learn where the organs are and become familiar with their locations. However, there's nothing wrong with clearing out blockages where you feel them until you get the "geography" in your head.
For now, maybe it's best for you to simply work with sensing the blockages and clearing them, then later start learning the location of each organ. There's so much to learn and put into our daily lives, it's really okay to do it a bit at a time. I trust my intuition when working on people and it hasn't steered me wrong yet.
