Centos 7 is merely driven by systemd – therefore things work slightly different than in Version 6.5.
Also the GUI completely lacks the /usr/sbin/servicesconf that once used to be there…
Well, this example shows how to enable MariaDB and Apache2 HTTPd on startup.
In order to get a list of all services and their current state:
systemctl list-unit-files
While one can grep the output (or scroll with shift + page up/down):
systemctl list-unit-files | grep mariadb
systemctl list-unit-files | grep httpd
In order to enable the services required:
chkconfig mariadb on
chkconfig httpd on