As @JordonBiondo reported here (this answer is a verbatim copy of his answer):

The procedure for reporting bugs, requesting features, and submitting pathces is outlined in the manual.

C-h rmBugsreturn

Or read online:

https://www.gnu.org/software/emacs/manual/html_node/emacs/Bugs.html

In a nutshell:

• use report-emacs-bug for bug reporting and feature requests
• ask the dev mailing list if you think your request requires more discussion
• check the existing bugs and search the mailing list to see if the topic has already been discussed and concluded upon
• read the manual for how to send patches
• subscribe to emacs-devel or even bug-gnu-emacs if you want to be more involved or informed about what is happening in emacs development.

Also read etc/CONTRIBUTE and BUGS

As @JordonBiondo reported here (this answer is a verbatim copy of his answer):

The procedure for reporting bugs, requesting features, and submitting pathces is outlined in the manual.

C-h rmBugsreturn

Or read online:

https://www.gnu.org/software/emacs/manual/html_node/emacs/Bugs.html

In a nutshell:

• use report-emacs-bug for bug reporting and feature requests
• ask the dev mailing list if you think your request requires more discussion
• check the existing bugs and search the mailing list to see if the topic has already been discussed and concluded upon
• read the manual for how to send patches
• subscribe to emacs-devel or even bug-gnu-emacs if you want to be more involved or informed about what is happening in emacs development.

Also read etc/CONTRIBUTE and BUGS