[argorain]

Try look for local FabLab or Maker/Hacker Space. People in there are usually willing to share their knowledge or they are even organizing some courses on that topic.

Either way, it's mandatory to understand electronics essentials (Ohm's law, Kirhoff's laws etc.) Try to find some electronics schoolbooks (I can provide something in czech only). After understanding basics, you can start with buses and digital communications (because digital is actually two level analog, right?)

Anyway, good luck.