Listed below is a summary of each one's offerings that should be of interest to the HF user. Utilizing some of the services available will provide a surprising amount of knowledge and operational capability.
Linkable text is underlined.
All three of the sites listed also contain substantial amounts of additional information and, once familiar with how the sites are laid out, the user can explore at will. But remember that the web, above all else, is an extremely dynamic medium and available data products will change. Contains daily 10 cm solar flux and A-index. Contains that day's Solar Flux value and A-index, plus forecasts for the next three. Canada's Space Weather center, the STD focuses great emphasis upon HF communications.