Published by the Australian Government, IPS Radio and Space Services

Book:

http://www.ips.gov.au/Category/Educational/Other%20Topics/Radio%20Communication/Intro%20to%20HF%20Radio.pdf

Website:

http://www.ips.gov.au

Mailing lists on HF Propagation:

http://www.ips.gov.au/Products_and_Services/4/1