All your solar &aurora needs in one place by Kevin, VE3EN
News & Information about the Sun-Earth environment
VHF Propagation map to help tell when the VHF bands are open and to where.
Solar Flares (Radio Blackouts) - NOAA
Explanation of Geomagnetic storms and the conditions that cause them- NOAA
HFTA- Generating Terrain Profiles and Tutorial by Stuart, K6TU