There are several written guides for starting worker cooperatives, and many more for starting cooperatives in general that include sections on worker cooperatives.  Having a good organizer or consultant, or mentor, surely makes any of the guides more useful.  A few examples are:

• Steps to Starting a Worker Cooperative by Gary Hansen, E. Kim Coontz, and Audrey Malan (1997)

• Empezando una Cooperativa de Trabajadores by E. Kim Coontz, CCCD. A Spanish-language version of Steps to Starting A Worker Co-op.

• In Good Company: the Guide to Cooperative Employee Ownership, a Worker Cooperative Toolbox  by Margaret Lund and the Northcountry Cooperative Development Foundation (2006)
• Starting a Worker Co-op: A Canadian Handbook produced by the Canadian Worker Co-op Federation (2009)
• How to Set Up a Workers' Co-op, Radical Routes, UK (2012)
• A Technology Freelancer's Guide to Starting a Worker Cooperative by Jim Johnson, Brent Emerson, et al (2009)
• Co-op 101: A Guide to Starting a Cooperative from the Cooperative Development Institute (2010)
• Putting Democracy to Work by Frank T. Adams and Gary Hansen (1987)
• Starting a worker owned cooperative for home care workers by Margaret Bau (2008?)

• Forming and Operating a Worker Cooperative.  A slide presentation at the 2010 Vermont Employee Ownership Conference by Newell Lessell of The ICA Group and Erbin Crowell of Co-operative Fund of New England.

• Cooperatives: A Tool for Community Development by Mary Myers , Greg Lawless , and E.G. Nadeau , University of Wisconsin Center for Cooperatives and Cooperative Development Services (1998)
• Considering Cooperation: A Guide for New Cooperative Development by Brian M. Henehan and Bruce L. Anderson, Department of Applied Economics and Management, Cornell University (2001)
• Cooperative Feasibility Guide by James Matson, USDA (2000)
• The Co-operative Formation Decision by Graeme Charles and David Griffiths, Cooperative Federation of Victoria, Australia, 2003
• How to Start a Cooperative by Galen W. Rapp and Gerald Ely (1996)
• Creating 'Co-op Fever': A Rural Developer's Guide to Forming Cooperatives, by William Patrie, USDA Rural Development (1998)
• A Legal Sourcebook for California Cooperatives: Start-Up and Administration by Van P. Baldwin (2004)
• Starting a Cooperative on the website of Cooperative Life
• Steps in Forming a Cooperative - a basic guide published by Cooperative Development Services, Madison WI.
• Cooperatives 101: An Introduction To Cooperatives by  Donald A. Frederick, USDA Rural Development (1997)

• “De empresa en crisis a empresa cooperativa”: Guía para la transformación de empresas mercantiles en cooperativas de trabajo. COCETA (Spain)

• Guide “Transmission d’entreprise en Scop”. CGScop (France)

• Creative cooperatives. A guide to starting a cooperative in the creative industries. Cooperatives UK

• Starting a Co-operative, Co-operatives UK