All of the additional resources for 1662 Book of Common Prayer: International Edition are available here--https://www.ivpress.com/pages/content/book-of-common-prayer-international-edition-free-resources-faq

Want to go further in depth on the readings for the First Sunday in Advent? Do you ever wonder why the traditional gospel for Advent 1 is Jesus cleansing the temple?
www.ivpress.com/Media/Defaul...

If you want to read more, here's "A Note on the Readings for Advent," one of the free resources hosted by @ivpress for the 1662 Book of Common Prayer: International Edition.
www.ivpress.com/Media/Defaul...

If you want to learn more about the Litany, a place to start is chapter 4 of "How to Use the Book of Common Prayer"--
www.ivpress.com/how-to-use-t...

In the classic Anglican prayer books, it's appointed at Morning Prayer every Wednesday, Friday, and Sunday.

One note about names. Beginning in the late twentieth century, some prayer books begin to call it the Great Litany, but that's just terminological inflation. It is great, but "the Litany" is the classic name in the Anglican tradition.