Since today is the last day of Polish American Heritage Month and I have been busy working on my personal research this month, I thought I should take a moment to recommend a learning resource.
FamilySearch's Learning Center includes several videos on Polish research. Cecile Wendt Jensen recorded two videos: Introduction to Polish Research and Advanced Polish Research, which are excellent companions to her book Sto Lat: A Modern Guide to Polish Genealogy.
While you are watching the videos, you will want to take notes. There are many websites she recommends, including those for archives in Poland with options to view the content in English. She also dispels some of the myths surrounding genealogical research in Poland and provides sound research advice for records in the United States, as well.
Below are links to the offerings at Family Search, as well as the Jensen's site, Michigan Polonia.
Family Search Learning Center: Poland
Cecile Wendt Jensen's Michigan Polonia