Thanks for your question. The My Lists is a feature of the National Archives Catalog and not a feature used in the Citizen Archivist program, that's why we don't have a tutorial about it. While logged in and searching the Catalog you can click on Add to my list while viewing a description. You can create a named list and add the record to that list. Then if you want to view this list you can access them within your Catalog account. My Lists is not visible to the public.
Community Manager, National Archives Catalog