I'd say stick with the Humane Society this summer. Dealing with animals will be easier than dealing with people and it will give you a chance to see how it works out for you in what should be the most stress free environment of the 3. Just don't take too many dogs home.
"If ye love wealth greater than liberty, the tranquility of servitude greater than the animating contest for freedom, go home from us in peace. We seek not your counsel, nor your arms. Crouch down and lick the hand that feeds you; May your chains set lightly upon you, and may posterity forget that ye were our countrymen."
Samuel Adams
ΜΟΛΩΝ ΛΑΒΕ