Locations and commands on the Mac OS X vs any other Linux/Unix system are different. Below are some of the locations and commands I ran across in setting up my macbook as a webserver.
apache2 is located in
/etc/apache2/
Along with the httpd.conf:
/etc/apache2/httpd.conf
By default apache2 logs are located at:
/var/log/apache2
By default files in the root directory are at:
/Library/WebServer/Documents/
To restart apache:
sudo /usr/sbin/apachectl restart
or
sudo apachectl -k restart
To Enable PHP, in httpd.conf remove the ‘#’ from this line:
#LoadModule php5_module libexec/apache2/libphp5.so