Bitcoin.org

[Joseph Young]

I'm a bitcoin client and software designer but i started to study coding it few days ago.

If i want to build bitcoin applications, is bitcoin.org developers guide the best place to start? or are their better places?

[David A. Harding]

It's certainly a good place to start. A few other good places to start
are listed in the Additional Resources section of the doc's main page:

https://bitcoin.org/en/developer-documentation

Please do let us know if there's anything we can do to make the
documentation more useful.

Have fun!,

-Dave
--
David A. Harding