Brine shrimp (artemia) molt 15 times before they reach adult stage. This takes roughly 3 weeks.
If kept at lower temps, they can be sustained for a few more weeks after that.
Brine shrimp are filter feeders and need very small particles in order to digest their food.
You can buy brine shrimp food prepared, or some say you can us brewers yeast, egg yolks, cod oil, Selcon, live algea cultures (presumably the best), and various other foods. Try searching the brine shrimp egg (cyst) suppliers web sites for more info on food.
I have a culture right now that hatched about 3 days ago and I am experimenting with the requirements to raise them to adult.
MCF