Questions like this degrade the professionalism of the field. Better programmers than any of us have to tried to cover the topic so generally, and they still came up with whole books that barely scratched the surface. If you want to know how to be a programmer, do some tutorials, then go to college for a few years, then work underneath an experienced professional for a few more years.

Can you imagine how silly it would sound applied to other fields?

"Hey guys, I decided to be a nuclear engineer/attorney/pilot/paramedic. What are the main things I need to know? I'll figure out the rest as I go along."