The books and videos available are ok. Nothing compares to time on the water. While you're shoulder is healing, consider hiring a guide. Take a trip with someone down the Sol Duc or Calawah, the more technical waters. Pay close attention to everything that the oarsman does. Ask questions, have them explain currents, back eddies, seams, etc. Everything you see on these two rivers will be duplicated, in a much less dramatic fashion, anywhere else you go.

Another good idea is to have an experienced oarsman sit in the front seat of your boat while you row. They can wave an arm showing you which oar you should hit for a while. You'll get the hang of it very quickly.