principle of moments

i don't understand how to determine clockwise and anticlockwise moments. i understand the whole seesaw thing because thats obvious. let me give an example. in 2) I've figured that the clockwise moments is 1500N x 1.2m. or is that anticlockwise...see i don't even know. assuming thats the clockwise, how would i know whats the anticlockwise moments about that point from the wall????

A moment is the turning action about a pivot caused by a force. i.e. acting to cause rotation about a fixed point (pivot).

The clockwise / anticlockwise movement is the direction of rotation caused by that force when referenced to the pivot.

In the example given, there is only one pivot (fixed to the upright wall) and one force anchored to that pivot (downwards force of 1500N person pulling on the camera). That force produces a clockwise moment about the pivot.

There is no anticlockwise moment because there is no force acting in the anticlockwise direction.

http://www.bbc.co.uk/schools/gcsebitesize/science/triple_aqa/using_physics_make_things_work/moments/revision/1/