I used to ride my bicycle to Radio Lab when they were in downtown Lubbock and look for stuff in their trash, maily speakers, magnets old TV parts and mercury batteries (which were great for making dimes shine - had no idea how dangerous they were).  Much later I got some of these magazines so I could to build some of the stuff in it.

This one has how to make a clock and a tutorial on making a voltage doubler, which is still widely used in electronics.  Daddy got me a crystal set when I was about 7.  There's one here that you can build in an oatmeal box!