Attorney General of Washington - Landlord/Tenant Law: General information about the state's Residential Landlord-Tenant Act.
Landlord.com: Resource network for landlords and property managers. Includes landlord law and advice.
Legal Information Institute: Landlord-Tenant Law: An overview of landlord-tenant law with links to key primary and secondary sources, from Cornell Law School's Legal Information Institute.
Nolo: Information about landlord and tenant issues.
RentLaw.com: An assortment of short articles, reference links, and affiliate book links, for landlords and tenants.
Tenanter: Sample residential lease agreement, customizable through an online interface.