Transportation Research Board ‘s (TRB) Airport Cooperative Research Program (ACRP) now has the Guidebook for Managing Small Airports—2nd Edition.
The first edition has been edited and reformatted for currency, relevance, and usability and updated with additional information and new subject areas (e.g., unmanned aircraft systems, geographic information systems, digital Notices to Airmen, social media, and federal and state obligations.
There is no charge for this publication.
Here is the link: http://www.trb.org/Main/Public/Blurbs/162145.aspx
You can also find it at the bottom of the WSDOT/Aviation page.
https://www.wsdot.wa.gov/aviation/Planning