The Oregon Department of Justice is charged with creating a number of manuals for use by state and local government in Oregon. These manuals are useful guides to the internal workings of Oregon's agencies and units of government. You can purchase these manuals from the ODOJ's website.
This site is especially useful if you are interested in obtaining public records in Oregon. The AG's Public Records and Meeting's Manual is available for free. It goes over the process of requesting records step by step. The book even includes samples and forms.
If you're planning on putting in a public records request in Oregon the Public Records and Meeting's Manual is a good place to start.