Lorenzo Snow Chapter 18: Church Leadership and Selfless Service- the first video on the right side, Sweet is the Work, is all about Relief Society service. The second video clip, Dayton's Legs is one of my favorites- definitely worth the 3 minutes.
"LDS Women are Incredible," by Elder Quentin L. Cook (Quorum of the 12 Apostles)- This one goes well with the "Sweet is the Work" movie. He talks briefly of the pioneer women then the women of today and our roles in the church and family.
"The Service that Counts" by President Thomas S. Monson (then 2nd Counselor in the 1st Presidency)- Great stories from the scriptures and from his life of service that really matters- great and small.
"Do Your Duty- That is Best" By President Thomas S. Monson (then 1st Counselor)- Speaking in Priesthood session he talks about the selfless service that should accompany priesthood duty.