On the Internet: Tenants can get information and forms at Washington LawHelp
At the Law Library: A packet from the above website called Eviction and Your Defense and other materials are available at the Law Library. The library might also have printed forms in other sections of the Washington LawHelp website that may be of interest, such as information about tenant rights and responsibilities, how to recover a security deposit, and how to try to stop an eviction after the court issued a Writ of Restitution. Some continuing legal education books discuss eviction, and you can consult the RCWs.
Landlords can purchase a form packet to evict a tenant. The forms are designed for landlords whose tenant has not paid rent or whose lease has expired. The packets are available in the Law Library for $60, including sales tax. The law library can accept cash or credit/debit (fee applies). The library also has materials that you can read about the eviction process.