An excellent book on the subject is "Transsexual Workers, An Employer's Guide" by Janis Walworth.
Other Transgender resources on this web site can be found at the Transgender Network web site: www.tgender.net and the Transgender at Work site: www.tgender.net/taw.
An excellent educational resource is the International Foundation for Gender Education, whose web site is at www.ifge.org. IFGE has an extensive book store with many useful books.