hi, I would like to know how to develop the Arduino hardwares, thanks a lot!
Too vague. Please spend some time to write a detailed explanation of what you are trying to accomplish.
I would like to develop an Arduino board,any board, can you tell me how?
You can start here:
After that, if you want to move on to making a PCB, there are many excellent tutorials available on the subject you'll find after a little effort on Google. You can get the schematics and design files for most of the official Arduino products on the "Documentation" tab of their product pages in the Arduino Store:
Have fun!
Why are you wanting to do these things ?