So I bought my first Arduino kit and it's quickly become apparent that I should really know more about electronics if I'm ever going to come up with my own projects. So I'm reading through a book on electronics and thinking there must be software that helps map out circuits. I've googled a few, but thought I'd get the opinions of people here.
Is there a good (preferably free) circuit drawing and dare I say testing software (open source?) that people like?
I see there are some open source projects and a few free ones from circuit manufacturers, but I'm not sure which one I should put time into learning?