There is a new book about time banking that looks great:

Equal Time, Equal Value: Community Currencies and Time Banking in the US, by Ed Collom, Judith N. Lasker, and Corinne Kyriacou. Burlington, VT: Ashgate, 2012.

It is rather expensive, but the Library of Congress has two copies, so anyone 18 and over can read it at the Library of Congress. It is super easy and fast to get a library card. And with your library card, you can sit in the cool rooms of the Library of Congress. In general, the Library of Congress is Great.

Here is the beginning of the book.

Here is a part of review from Contemporary Sociology:

In Equal Time, Equal Value, Ed Collom, Judith Lasker, and Corinne Kyriacou present the first, and most exhaustive, systematic investigation of the most popular type of localized exchange system in the United States — Time Banking. Drawing on data collected using multiple methods — a national survey of Time Bank coordinators; interviews with founders, coordinators, and participants; participant observation; three in-depth case study surveys; and secondary data analysis — the authors move beyond limited snapshots of individual organizations to present a focused and well-manicured Time Banking textbook, complete with history, organizational types and demographics, profiles of participants and their motivations for joining, and perceived benefits/outcomes…

Here is the DC Time Bank: https://dc.timebanks.org/.