Is it better to have my compost pile in the sun, or in the shade? I have space on the north and south walls of my house, and want to know which would be a wiser place for the pile.
It depends a lot on your climate and what you're putting in your compost.
Compost likes to be warm, so sun helps.
Compost likes to be moist - like a wrung-out sponge. If the sun would cause it to over-dry in the summer, or the shade would allow it to become over-wet in the winter, then you'll need to adjust accordingly.
You can add water to a compost pile, but using fresh drinking water that way seems counter to the very purpose of composting. Greywater is a good choice, and it includes some additional nutrients.
If your compost is too wet, you can dry it out by mixing in some dry sawdust. I don't recommend wood shavings, however, because they break down very slowly. (It's unfortunate, because wood shavings are an abundant waste product.)