I have installed apache from the source with:prefix=/usr sysconfdir=/etc/httpd/ localstatedir=/var.
useradd -g apache -d /usr/apache -s /sbin/nologin apache
If you wonder about the home directory, it should not matter that much, because it will probably not change the behavior of apache at all.
On Debian, the default homedir for the user running apache is /var/www (which is the default DocumentRoot).
Also, if you're on a Debian-based distrib, you should prefer using adduser instead of useradd which is quite low level.
adduser is a symlink to useradd in RHEL. The upstream for adduser in Debian, is actually Debian, so I would consider it Debian-specific.
/usr/local, to keep things separate from software provided by your OS.