Hey, this is NOT a comprehensive guide to setting up your own development environment, but I thought I’d post a few pitfalls I’ve discovered.
Most macs are set up out of the box to run apache found in /etc/apache2/. Normally, the system user and group for apache is _www. If you try to set up sites in /usr/HOMEDIR/Sites, it’ll likely give the files there the ownsership:group of YOURUSER:staff (or something else than staff). It either needs to be _www:_www OR YOURUSER:_www (and then you change the httpd.conf file to reflect YOURUSER for the User variable).
Also to edit any system files like that, be sure to edit as a super user or sudo.