How do you play Hearts of Iron 3? I don't understand it. And don't say play the tutorial because we all know paradox can't make a good tutorial
I got it awhile ago and I'm just starting to get it. Start as like the uk or Germany, watch some videos, and just try some stuff out. The most complicated stuff is army organization and supply. Many players put automated trade on in diplomacy, which means you won't get spammed with trade agreements and the AI will automatically make the best ones.
Also you should get all the big DLCs. They really change the game (for the motherland, semper fi, their finest hour)