They eggs float. So, you can drain the baby brine out of the bottom of the container. You can buy the eggs at almost any pet store. I believe http://livebrineshrimp.com/ has higher quality eggs.
Hatching is easy. You can get the hatching kits at pet stores as well. Tt just takes a container with a valve in the bottom(to get the shrimp out), an airtube, and some old tankwater. Pretty much combine those things and the eggs. Wait 24-48 hours and you have baby brine. You then open the valve on the bottom and drain the water into a brine shrimp net. The shrimp will get caught and the water will go through.
Mandarins love baby brine!
I have to say Willow sounds like the brine expert.