Some important resources on this subject include:
A Description of the Qualifications Necessary to a Quaker Minister by Samuel Bownas. This thin but powerful volume is the classic Quaker treatise on this subject.
A Few Passages Relating to Elders & Ministers prepared by Bob Schmitt, Jan Hoffman and Kenneth Sutton
Elders posted by West Hills Friends (in Portland OR)
Echoes from a Worship & Ministry Retreat Concerning Eldering from Stony Run Meeting in Baltimore
Eldering then & now by Liz Oppenheimer
Selected Bibliography on Ministry and Eldering prepared by the FGC Traveling Ministries Program
Three important pamphlets that are not currently available online include:
Gospel Order: A Quaker Understanding of Faithful Church Community by Sandra Cronk.
: Papers from Ohio Yearly Meeting's Gathering on Eldering
Tall Poppies: Supporting Gifts of Ministry & Eldering in the Monthly Meeting, by Marty Grundy, Pendle Hill Pamphlet # 347, 1999.
We would welcome hearing from others regarding additional resources on this subject that you have found particularly helpful.