Learn the basic concepts and then go from there. That's my advice. I learned on the Moog Modular which was cool because it was easy to grasp all the routing especially for learning purposes.
I agree. Those Sound On Sound articles are the bomb.
But there's nothing like hands on learning, and here's a link to some free synths of varying complexity. The Novakill K1 is one they recommend for learning synth basics.
Learn the basic concepts and then go from there. That's my advice. I learned on the Moog Modular which was cool because it was easy to grasp all the routing especially for learning purposes.