circuit design

Reading this thread, something comes into my mind:
Several years ago - at the beginning of my membership to another electronic-oriented forum - I did open a new thread with a provocative question "Is this forum dangerous"?
The background of my question was the following:
I was (and still I am up to a certain degree) afraid that the opportunity to ask simple and basic questions could prevent beginners from doing their own research activities - primarily reading/evaluating relevant book chapters.
I think, this thread is an excellent example.
W.

You won't go far wrong with "The Art of Electronic" by Horowitz & Hill. Buy it. It's worth every penny and is considered the industry bible. It covers many areas of electronics designs, the do's and the dont's.