Help Required?

[gh74]

ok in the first  photo can someone help me with what that we pipe coming out off the skimmer unit is for and what it should be connected too?
 
the pic of the uv sterilizer i know one pipe goes to the filter then were is the other pipe going to so i can get all this set up correctly.
 

 

 

[gh74]

Ok i know on the uv sterilizer  one end connects to the filter,so does the other end just sit in the water fir it to be returned the water?
 
and for the valve on the skimmer does it need to be vertical or horizontal for it to work etc?