newbie question: how to get more than one user to be in the GROUP for directory ownership?

I need "apache" and my username to share access to a directory because my
php script creates directories within a directory.

For example the directory /home/html/mysite/files, I want apache to be able
to create directories and file and I need to see those files and directories
when I use WinSCP using my username to login.

Currently, I did this and it allows the script to write directories:
chown username:apache files

I use WinSCP (which logs in using username) to check out what's inside those
directories and it errors out, permission denied.

Any ideas are much appreciated!