Most of the training courses for the entry level are little too mickey mouse imho - and mostly sales exercises rather than technical. I would:
- Join the Institute of Sound and Communication Engineers and go to their events/seminars
- Consider joining CEDIA
- Take an HDMI course e.g. Aldous Systems
- Familiarise yourself with building regs - approved documents B, L, M and P.
- Get some work experience or an entry level installer job to learn the practical side
Was interested in the networking side too, and thought seemed quite good value for what small bit of knowledge you would get, do you have any other ideas in general? I saw this course when looking for a HDMI course like you recommended above?