Here are some resources for Shavuot learning.
David Hartman – “Shavuot and the Meaning of the Covenant”
Marcie Lenk – “Shavuot. Pentecost. Harvest. First Fruits. Revelation at Sinai. Holy Spirit. Torah.”
Shraga Bar-On – “How Shavuot Became the Festival of the Giving of the Torah”
Donniel Hartman – “On Shavuot, Reverse the Paucity of Ideas That Threatens Judaism, Israel”
Elana Stein Hain – How to Move Mountains: Questions for North American Jewry
Megillat Ruth
Micah Goodman – “Shavuot: Megillat Ruth and ‘Matan Torah’ to the World”
Tamara Mann Tweel – “The Exquisite Challenge of Care (Shavuot)”
Noam Zion – “To Be ‘Remaindered’: The Book of Ruth’s Naomi as Mourner”
Channa Pinchasi – “Women, Come and Read All of the Megillot”
Videos
Orit Avnery – Book of Ruth – Between Acceptance and Alienation (Shavuot 5779)
Christine Hayes – Moses at Sinai – God’s Partner or Adversary? (Shavuot 5776)
Christine Hayes – Introduction to the Hebrew Bible
Yossi Klein Halevi & Haroon Moghul – Particularism and Universalism: Reflections on Revelation and Jewish Identity
Donniel Hartman – Shavuot Teaches That Ideas Matter
Rachel Sabath Beit-Halachmi – Three Models of Torah on Celebrating Shavuot
Complete playlist of Hartman Shavuot videos (English and Hebrew)