Front of head = "Yang Ming" headache. For that one you can try the acupoint between your first finger and thumb. Its in that web back towards the bone. You can massage there or press hard. I like the cool stones on the top of the head for that too. If you google image "Large Intestine 4" you can get a picture of where it's at.
Side of the head= "Shao Yang" headache. For that there's a technique called a 5 finger grasping. It's hard to describe but basically you grasp the sides of your heads and pull up and roll the skin between your fingers (sort of like a shampoo).

The stones massaged around the temples can work too.
Back of the Head = "Tai Yang" headache. This can often be alleviated by massaging the back of the neck as long as it's not a sign of impending cold or flu.