Playing Soul Silver trying to figure out how EV's and IV's work

EV's I get from grinding off certain pokemon?

IV's are genetic?

So let's say I hatch a pokemon from an Egg where do I locate it's EV's and IV's? What IV's are considered good?

And when I hatch the pokemon from the egg do I grind the normal way or do I give it the EXP share? I wanna give it the EXP share but i'm not sure that would fuck up the process.