A few ideas for programs:
I agree with HF propagation, that would be a good subject;
–Traffic handling (NTS nets, Radiograms)
–Contesting
–Antenna builds
–Various digital modes, i.e. RTTY, SSTV, Winlink, Vara (HF & VHF), JT/FT modes, etc., as well as basic set-up
–APRS
–Digital radio modes (System Fusion & WIRES-X, D-Star, etc.)
–Satellite operations
–RDF/Fox Hunting
–HF/VHF/UHF Net Operations (mostly geared possibly for new hams)
–Emergency Communications and AUXCOM
–Amateur Radio Emergency Service (ARES)
–Community Emergency Response Team (CERT – while not specifically amateur radio related, it does benefit)
–Project builds
Hope this list helps. I’m sure there’s plenty other things since ham radio is “a thousand hobbies in one.”