First of all, what is your academic background? There are lots of guys coming out of the various colleges that specialize in avionics training.
Secondly, do you want to work in the shop or on the hangar floor doing line maintenance/install? Or both? They are quite different jobs requiring unique skills.
If you want to work in the shop and fix radios, many of the avionics courses out there have very little to offer.
So, what's your situation?