su & sudo on OSX Mavericks
dsenableroot -u $ADMIN_USERNAME -p $ADMIN_PASSWORD -r $ROOTSNEWPASSWORD


replace the variables with your admin username and password as well as the password you desire for root.  At that point, you could sudo as the admin user or just su - and use the root password you set to become root.

In the end, you'll want to either configure sudo to allow the commands you use often from your non-admin account or get used to typing the root password when needed.