Hot water valve in the basement (how do I turn it off?)

If you have a 1/4 turn ball valve then there should be stops protruding from the unit which prevent it from being turned too far. Look for something similar to this picture and you'll be able to determine the proper direction of rotation.

In this picture it is in the ON position, parallel to the water line. You need to make the handle perpendicular (imagine the letter T) to shut the water OFF.

If it feels seized up then make sure to hold the pipe firmly because copper is a soft metal and you could deform (or worse, rupture) it while trying to turn your valve. If in doubt then it's time to call a plumber.

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If you have a gate valve then righty-tighty, lefty-loosey :)

The green arrow shows the direction to turn to close it. The purple arrow shows the packing nut discussed in the comments.

I'm not sure what you mean about North, South, etc but if this thing is installed in the ceiling with the red handle pointing up, you could stand directly below it, reach up and over it with your hand to grab it from above, then turn your body to the right.